PRD/SZNS 077: 202 3  
  
ICS                                   Edition 1  
   
    
    
 
 
 
 
 
 
 
   
  
 ESWATINI NATIONAL STANDARD  
   
    
    
 
 
 
 
 
   
Eswatini Electricity Safety Standard   
    
   
  
     
   
 
 
 
 
 
 
  
Published by: Eswatini Standards Authority  
Marble Construction Building, Plot 247 11th Street King Mswati III Avenue West  
P. O. Box 1399, Matsapha, Kingdom of Eswatini   
Telephone: +268 2518 4633, Facsimile: +268 2518 4526   
Website: www.swasa.co.sz   
E-mail: info@swasa.co.sz    
©Eswatini Standards Authority 202 3  PRD/ SZNS  077: 202 3 
 Edition 1  
2 
© Eswatini Standards Authority 202 3   
All rights reserved   
   COPYRIGHT NOTICE  
This Eswatini Standards Authority (SWASA) document is a National Public Review  Draft 
standard and is copyright  protected by SWASA. Neither this SWASA document nor any extract 
from it may be reproduced, stored in a retrieval system or transmitted in any for m or by any means, 
electronic, photocopying, recording or otherwise, without prior written permission being secured.  
 
Requests for permission to reproduce shall be addressed to:  
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Eswatini Standards Authority  
P.O. Box 1399, Matsap ha   
Tel. + 268 2518 4633  
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Website: www.swasa.co.sz   
Reproduction may be subject to royalty payments or a licensing agreem ent.  
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 PRD/ SZNS  077: 202 3 
Edition 1  
3 
© Eswatini Standards Authority 2023   
All rights reserved   
   Table of changes  
Clause Changed   Date  Change   
      
 
NATIONAL FOREWORD  
This Eswatini National Working  draft Standard was prepared by Technical Committee SWASA/TC 
36 Electrical Energy and Wiring  in accordance with procedures of the Eswatini Standards 
Authority, in compliance with Annex 3 of the WTO/TBT Agreement.  
  
  
  
  
     PRD/ SZNS  077: 202 3 
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All rights reserved  Table of Contents  
0 Introduction  ................................ ................................ ................................ ...............  9 
1 Scope  ................................ ................................ ................................ .......................  11 
2 Normative References  ................................ ................................ .............................  11 
3 Terms and definitions  ................................ ................................ ..............................  11 
3.1 Officials Persons ................................ ................................ ................................  11 
3.2 Operating Terms  ................................ ................................ ................................  13 
3.3 Printed Forms, Books and Notices  ................................ ................................ ............  25 
4 Control of a Power System  ................................ ................................ .....................  26 
4.1 Duties and Responsibilities of a System Controller  ................................ .........  26 
4.2 Keeping of Records ................................ ................................ ...........................  27 
4.2.1  Operating records  ................................ ................................ ......................  27 
4.3 Issue and Receipt of Operating Instructions and the Use of Operating 
Instruction Forms  ................................ ................................ ................................ ........  28 
4.3.1  Permission to operate ................................ ................................ .................  28 
4.3.2  Report back on completed operating  ................................ .........................  30 
4.4 Relay of operating instructions through a third pe rson ................................ ..... 30 
4.5 Issue and receipt of pre -authorised instructions ................................ ................  30 
4.6 Circumstances when an operating instruction shall be cancelled  .....................  31 
4.7 Control of Loading of Power Stations Under Normal and Abnormal 
Conditions  ................................ ................................ ................................ ...................  32 
4.8 Control and Loading of Transmission and Distribution Apparatus  ..................  33 
4.9 Order of Precedence in Use of Communication System  ................................ .. 33 
4.10  Commissioning of Apparatus on First Installation or After Alteration or 
Repair  33 
4.11  Use of Operating Diagram/Mimic  ................................ ................................ . 34 
5 Access  ................................ ................................ ................................ .....................  34 
5.1 Access to Live Chambers , restricted areas  and Prohibited Areas  .....................  34 
5.1.1  Persons authorised to enter live chambers , restricted areas  or prohibited 
areas  34 
5.1.2  Informing the system controller when accessing a live chamber  ..............  34 
5.1.3  Informing the system controller when accessing a prohibited area ...........  35 
5.1.4  Informing the system controller when accessing a restricted  area ............  35 
5.1.5  Locking of doors and gates  ................................ ................................ ........  35 
5.2 Procedures for Access to Live Chambers of Persons other than Persons 
Authorised  ................................ ................................ ................................ ...................  35 
5.3 Procedures for Access to Prohibited Areas of Persons other than Persons 
Authorised  ................................ ................................ ................................ ...................  36 
5.4 Duties to Perform when Gaining Access to Prohibited Areas or Live 
Chambers  ................................ ................................ ................................ .....................  36 
5.5 Staying Overnight in Live Chambers or Prohibited Areas  ...............................  36 
5.6 Electric Fences  ................................ ................................ ................................ .. 37 
5.7 Procedures for Access of Persons to Restricted Areas other than Persons 
Authorised  ................................ ................................ ................................ ...................  38 
5.8 Access to and Work in Fire Protected Areas  ................................ ....................  38 
5.8.1  Automatic Control  ................................ ................................ .....................  38 
5.8.2  Portable Fire Extinguishers  ................................ ................................ ....... 38 PRD/ SZNS  077: 202 3 
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All rights reserved  5.8.3  General  ................................ ................................ ................................ ....... 38 
6 Keys  ................................ ................................ ................................ .........................  39 
6.1 Issuing and Control of Master Keys  ................................ ................................ . 39 
6.2 Issuing and Use of Station Keys  ................................ ................................ ....... 39 
6.3 Issuing and Use of Personal Safety Padlocks  ................................ ...................  39 
7 Work Permits  ................................ ................................ ................................ ..........  40 
7.1 Circumstances When A Work Permit Is Required  ................................ ...........  40 
7.2 Forms in Duplicate  ................................ ................................ ............................  40 
7.3 Use of Work Permit Form ................................ ................................ .................  40 
7.3.1  Application  and permit  ................................ ................................ ..............  40 
7.3.2  Work permit  ................................ ................................ ...............................  41 
7.3.3  Worker’s declaration  ................................ ................................ .................  41 
7.3.4  Clearance  ................................ ................................ ................................ ... 41 
7.3.5  Return to service  ................................ ................................ ........................  42 
7.3.6 Non-availability of original form  ................................ ..............................  42 
7.3.7  Original forms ................................ ................................ ............................  43 
7.3.8  Duration of permit  ................................ ................................ .....................  43 
7.3.9  Work may only be done under one permit at a time  ................................ . 43 
7.3.10  Issuing of more than one permit  ................................ ................................  43 
7.3.11  Work permits are required for each circuit  ................................ ................  43 
7.3.12  Work on apparatus involving licensees, customers and contractors  .........  43 
7.3.13  Cases  where  a work  permit  is not required : ................................ ..............  44 
8 Authorized Operation  ................................ ................................ ..............................  44 
8.1 Persons Authorised to Perform Switching, Linking, Safety Testing and 
Earthing Operations  ................................ ................................ ................................ .... 44 
8.2 Procedure for Work in Live Chambers  ................................ .............................  44 
8.3 Making Feeders and Apparatus Safe to Work On  ................................ ............  45 
8.3.1  All operating to be carried out under instruction from the system 
controller  ................................ ................................ ................................ .................  45 
8.3.2  Emergency switching  ................................ ................................ ................  45 
8.3.3  Isolating from supply under direct instruction from system controller  ..... 45 
8.3.4  Links and drop out fuses  ................................ ................................ ............  46 
8.3.5  Bypassing of interlocks  ................................ ................................ .............  47 
8.3.6  Safety -testing of feeders and apparatus after isolating from supply  .........  47 
8.3.7  Warning notices and earth labels  ................................ ...............................  47 
8.3.8  Earthing  ................................ ................................ ................................ ..... 48 
8.3.9  Work on lines ................................ ................................ .............................  51 
8.3.10  Work on insulated conductors and underground cables  ............................  54 
8.3.11  Work  in stations  with exposed  live conductors  ................................ .........  54 
8.3.12  Use of ladders and long objects  ................................ ................................ . 55 
8.3.13  Metal clad switch gear  ................................ ................................ ...............  56 
8.3.14  Work on transformers  ................................ ................................ ................  57 
8.3.15  Testing of medium and high voltage equipment  ................................ ....... 58 
8.3.16  Work on low voltage systems  ................................ ................................ .... 58 
8.4 Returning Feeders and Apparatus to Service  ................................ ....................  59 
8.4.1  Under normal conditions  ................................ ................................ ...........  59 
8.4.2  When the responsible person or appointed operator is not available  ........  60 PRD/ SZNS  077: 202 3 
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© Eswatini Standards Authority 202 3   
All rights reserved  8.5 Exemption from General Procedure  ................................ ................................ . 60 
8.5.1  Work to be done on a line controlled from a single source of supply  ....... 60 
8.5.2  Replacing of drop out fuse links without reference to the system 
controller  ................................ ................................ ................................ .................  61 
8.5.3  Dual line systems  ................................ ................................ .......................  61 
8.5.4  Station isolation  ................................ ................................ .........................  61 
8.6 Supervision of Work  ................................ ................................ .........................  62 
8.7 Temporary Absence of Persons in Charge of Work  ................................ .........  62 
8.8 Testing Apparatus  ................................ ................................ .............................  62 
8.9 No Operating While Work is in Progress in Live Chamber  .............................  63 
9 Abnormal Conditions  ................................ ................................ ..............................  63 
9.1 Abnormal Conditions to be Reported to System Controller  .............................  63 
9.2 Emergency Switching  ................................ ................................ .......................  63 
9.3 Communication System  ................................ ................................ ....................  63 
9.4 Restoration of Supply in the Absence of Communication ................................  63 
9.5 Establishment of Local Control Centre  ................................ .............................  64 
10 Live Work  ................................ ................................ ................................ ...............  64 
10.1  Abnormal Co nditions to be Reported to System Controller  .........................  64 
10.1.1  Persons in charge of live work  ................................ ................................ .. 64 
10.1.2  Persons who may perform live work  ................................ .........................  64 
10.1.3  Persons who may deputise for the responsible person  ..............................  64 
10.2  Live Work at Power Stations or on the Distribution System  ........................  65 
10.2.1  Circumstances requiring a live work declaration form  .............................  65 
10.2.2  Forms in duplicate  ................................ ................................ .....................  65 
10.2.3  Preparation and handing  over of apparatus for live work  .........................  65 
10.2.4  Issue of a live work declaration form  ................................ ........................  66 
10.2.5  Cancellation or Closing of a live work declaration form  ..........................  66 
10.2.6  Original and duplicate forms  ................................ ................................ ..... 66 
10.2.7  Restrictions on re -closing breakers ................................ ............................  66 
10.2.8  Duration of live work declaration  ................................ ..............................  67 
10.2.9  When the responsible person is not available  ................................ ............  67 
10.3  Supervision of Live Work  ................................ ................................ .............  67 
11 Design and Construction  ................................ ................................ .........................  68 
11.1  General  ................................ ................................ ................................ ..........  68 
11.2  Normative Standards  ................................ ................................ .....................  68 
11.3  Equipment and Material  ................................ ................................ ................  70 
11.4  Clearances of Power Lines  ................................ ................................ ............  70 
11.4.1  Minimum clearances to other services  ................................ ......................  70 
11.4.2  Standard Minimum Electrical Clearances/Distances  ................................  72 
11.4.3  Minimum Safety Clearances  ................................ ................................ ..... 73 
Table 3:  Minimum safety clearances  EEC to review  ................................ .............  73 
11.4.4  Clearances between parallel independent structures  ................................ . 74 
11.4.5  Clearances between circuits on common structures  ................................ .. 74 
11.4.6  Clearances between conductors of lines with a vertical configuration  ..... 74 
11.4.7  Aerial bundle conductors  ................................ ................................ ...........  74 
11.4.8  Induced voltages  ................................ ................................ ........................  74 
11.4.9  Electrolytic corrosion  ................................ ................................ ................  75 PRD/ SZNS  077: 202 3 
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All rights reserved  11.5  Conductors and Earth Wires for Power Lines  ................................ ...............  75 
11.5.1  Corrosion  ................................ ................................ ................................ ... 75 
11.5.2  Minimum size  ................................ ................................ ............................  75 
11.5.3  Current -carrying capacity  ................................ ................................ ..........  75 
11.5.4  Maximum tensions  ................................ ................................ ....................  76 
11.5.5  Sag charts  ................................ ................................ ................................ ... 76 
11.5.6  Creep  ................................ ................................ ................................ ..........  76 
11.5.7  Joints  ................................ ................................ ................................ ..........  77 
11.6  Power Line Structures  ................................ ................................ ...................  77 
11.6.1  Factors of safety ................................ ................................ .........................  77 
11.6.2  Design Loading ................................ ................................ ..........................  77 
11.6.3  Loading due to broken conductors  ................................ ............................  78 
11.6.4  Erection loads  ................................ ................................ ............................  78 
11.7  Foundations for Power Line  ................................ ................................ ..........  79 
11.8  Insulators and Fittings  ................................ ................................ ...................  79 
11.8.1  Mechanical strength requirements  ................................ .............................  79 
11.8.2  Electrical insulation levels and footing resistance requirements  ...............  79 
11.8.3  Insulation levels in polluted areas  ................................ .............................  81 
11.9  Stay Wires  ................................ ................................ ................................ ..... 82 
11.9.1  Installation of stays  ................................ ................................ ....................  82 
11.9.2  Factor of safety  ................................ ................................ ..........................  82 
11.10 Earthing  ................................ ................................ ................................ .........  83 
11.10.1  Support structures for power lines  ................................ .........................  83 
11.10.2  Earth wires  ................................ ................................ .............................  83 
Annex 1:  Operating Instruction Form  ................................ ................................ ...............  A 
Annex 2: Operating Authority  ................................ ................................ ...........................  B 
Annex 3: Work Permit Form  ................................ ................................ .............................  C 
Annex 4: Live Work Declaration Form  ................................ ................................ ............  F 
Annex 5: Worker’s Declaration  ................................ ....... Error! Bookmark not defined.  
* Delete which is not applicable ...............................  Error! Bookmark not defined.  
Annex 6: Control Panel Label/Tag  ................................ ................................ ....................  H 
Anne x 7: Access Keys Register  ................................ ................................ .........................  I 
 
 
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  PRD/ SZNS  077: 202 3 
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© Eswatini Standards Authority 2023   
All rights reserved  0 Introduction   
0.1 Standard Governance Framework   
The following  diagram  illustrates  the extent  of interaction  among  the key stakeholders  in the 
Eswatini Electricity  Industry  as far as the administration  and enforcement  of the electricity  
safety  standards  are concerned.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 Government  
Ministry of Natural Resources 
and Energy (MNRE)  
Eswatini Energy Regulatory 
Authority (ESERA) 
(ESERA)  
Market Participants  • Energy Policy Advisory Committee  
• Energy Department  
• Renewable Energy Unit  
• National Energy policy Implementation Strategy 
(NEPIS)  
• Legislation – Electricity & Regulation Act  
• Eswatini Electricity Company (EEC)  
• Independent Power Producers (IPPs)  
• Neighboring Utilities e.g. ESKOM, EDM  
• Distributors/Customers  Ministry of Commerce, 
Industry and Trade (MCIT)  
Eswatini Standards 
Authority (SWASA)  
• Standards Advisory Committee  
• Standards Technical Committee  
• Sale of Standards  
• Electricity Licensing By -laws  
• Guidelines, Directives, Rules, Codes – Grid 
Code  
• Technical Standards - Quality of Supply & 
Services  
• Tariff Methodologies  PRD/ SZNS  077: 202 3 
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All rights reserved  0.2 Safety Governance Organisational Structure   
0.1 The following  organogram  serves  to illustrate  from  a safety  governance  perspective,  and 
it among  the various  ‘Key  role players  within  the organisational  structure  of a licensee.  
0.2 The vertical  and/or  horizontal  extension  or curtailment  of this structure  depends  largely  
on the size and unique  organisational  structure  of each licensee.  
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
1. Every  licensee  shall  be in possession  of a copy  of this Standard  and all relevant  legislation  
pertaining  to the Eswatini  Electricity  Industry.  The licensee  is responsible  for complying  
with the minimum  safety  standards  prescribed  in this Standard  and for ensuring  that all 
relevant  role players  within  the licensee’s  organisation  are acquainted  therewith.  
2. The licensee  may assign  in writing  the responsibility  for enforcing  compliance  and 
adherence  to the safety  standards  prescribed  in this Standard.  
3. Where  an interconnection  exists  between  two or more  power  systems,  whether  between  
two licensees  or between  a licensee  and another  power  producer  or distributor,  appropriate  
communication  and coordination  means  must  be established  and maintained  with regard  to 
operational  matters  under  joint authority . Licensee  
MD/ CEO  
Responsible  
Official  
Power Station Control  
Room Official  Official in Charge  Official in Charge  
System Controller  
Approved Operator  Authorized Person  
Authorized Operator  
Responsible Person/ 
Contractor  Responsible Employee  
Responsible 
Person/ Contractor  PRD/ SZNS  077: 202 3 
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All rights reserved  Eswatini Electrical Safety Standards   
1 Scope   
1.1 This Standard governs  the minimum  safety  standards  for the operating,  maintenance,  
construction  and installation  of power  systems  in Eswatini . The purpose  of this Standard is 
threefold,  namely,  to ensure  the safety  of all persons,  to safeguard  apparatus  and to ensure 
continuity  of supply.  
1.2 This Standard is an extension  of, and must  be read in conjunction  with,  the provisions  of 
the Electricity  Act of 2007 ; Factories, Machinery and Construction Works Act 17 of 1972 
and the Operational Safety and Health Act 9 of 2001 (with  particular  emphasis  on the Health  
and Safety  Act  made  thereunder),  and all other  applicable  laws,  and does not supersede,  
overrule  or negate  any provisions  contained  in the Electricity  Act, the Labour  Act or such 
other  laws.   
2 Normative References   
The following referenced documents are indispensable  for the application of this document.  
3 Terms and definitions   
For the purpose of this standard the following definitions and abbreviations apply.   
3.1 Officials Persons  
In this Standard,  including  its introduction,  unless  the context  otherwise  indicates  - 
Appointed operator  (A/O)  
a qualified  person  authorised  to carry  out safe operating  on the power  system  of a licensee  
on instruction  of the system  controller  in accordance  with this Standard;  
Authorised  person  (A/P)   
a competent person  who has been  appointed in writing by an authorized entity to carry out 
duties specified in writing (which may include authority to issue , cancel  or close safety 
documents including but not limited to  limitations -of-access  and/or to receive sanctions -for-
test. 
Competent person  
a person  certified by the licensee  as having sufficient technical knowledge and/or experience 
to enable them to avoid danger  and who may be nominated by a n authorized entity  to 
receive, transfer and clear specified safety documents . 
Contractor  
a person  contracted  to do work  on a power  system  in accordance  with this Standard;  
Consumer  
A person supplied or entitled to be supplied with electricity by any licensee or supplier ; 
Customer   
a person  to whom  electricity  is delivered  by a licensee,  and includes  a consumer;  
 PRD/ SZNS  077: 202 3 
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All rights reserved  Inspector  
a person  appointed  as a labour  inspector  under  section  124 of the Labour  Act; 
Instructed Person (I/P)  
A person adequately advised by an authorized person or who has sufficient training and 
experience in the safety requirements for the work being undertaken to enable them to avoid 
the dangers which electricity may create.  
Licensee  
the holder  of a license granted or deem to be granted by the authority under the Energy 
Regulatory Act of 2007 for the generation, transmission, distribution and supply of 
Electricity . 
Minister  
the Minister  responsible  for Energy  Affairs ; 
Official in charge   
a qualified  person  employed  by a licensee,  who is - 
1 in charge  of a defined  section  of a power  system;  and 
2 authorised  to make  decision s and give instructions  on deviations  from  normal  operating  
procedures;  
Power station control room official  
a person  deployed  by a licensee  in the power  station  control  room  and generally  in control  
of the operation  of a power  station  in accordance  with this Standard;  
Qualified person  
a person  who is able to submit  documentary  proof  that he or she has - 
1 received  appropriate  theoretical  and practical  training;  and 
2 gained  adequate  experience  in electricity  safety;  
Responsible official  (R/O)  
a qualified  person  employed  by a licensee,  who is responsible  for ensuring  compliance  and 
authorising  persons  to ensure  compliance  with this Standard,  and in the event  of no such 
person  being  employed  by the licensee,  means,  in the case of the licensee  being:  
1 A company,  the managing  director  or chief  executive  officer;  
2 a close  corporation,  the managing  member;  
3 a trust,  the chairperson  of the board  of trustees;  
4 a partnership,  the managing  partner;  
5 a proprietorship,  the owner;  
6 an association,  the chairperson  of the executive  committee  or management  committee;  or 
7 a co-operative,  the chairperson  of the board  of directors;  
Responsible person  (R/P)  
 a person  who has been  authorised  to work  on apparatus  covered  in a work  permit  or a live 
work  declaration;  this may include authorized person, competent person and instructed 
person.  
Responsible employee  (R/E)  
 a person  employed  by a licensee,  who is responsible  for ensuring  that any work  on apparatus  
in terms  of this Standard  can be carried  out with safety;  
System  controller  (S/C)  
a person  on duty,  who is responsible  for- PRD/ SZNS  077: 202 3 
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All rights reserved  1 the general  operation  and control  of a power  system;  and 
2 the issuing  of instructions  to an appointed  operator  or authorised  person  for the safe 
operation  of generation,  transmission  and distribution  systems  in accordance  with this 
Standard;  
Worker   
a person  employed  to work  on a power  system.  
3.2 Operating Terms  
In this Standard,  including  its introduction,  unless  the context  otherwise  indicates  - 
Abnormal condition  
Failure or interruption of a system that can cause overloading  
Chassis   
a commercial  vehicle  or trailer  (frame)  on which  the insulating  aerial  device  is mounted  to 
perform  live work;  
Electrical distance  
 The electrical  distance  in air, which  protects  against  electrical  breakdown,  namely  the 
minimum  distance  between  two electrodes  required  to ensure  that the probability  of 
electrical  breakdown  is negligible  when  subjected  to the most  severe  electrical  stress  likely  
to arise  under  the conditions  stipulated  in this Standard,  which  may refer  to phase -to-phase  
or phase -to-earth  distances  and also to electrical  distance,  ergonomic  distance  and safe 
working  distance;  
Ergonomic distance  
the distance  that allows  for inadvertent  body  movement  and judgment  of distances  during  
the work  required  to be carried  out at the minimum  safe working  distance  when  performing  
live work,  and includes  electrical  distance  and safe working  distance;  
Insulate d 
covered,  enclosed,  surrounded  or supporting  live conductors  or apparatus  with insulating  
material  of such thickness  and properties  that it will prevent  the flow of electricity  or 
potential  between  the object  so covered  and its surroundings  or any external  object  in contact  
with it including  the prevention  of making  contact  with earth;  
Insulating aerial device  
 An aerial  device  comprising  an insulating  boom  designed  to position  the competent person  
and the equipment  for live working,  which  device  is mounted  in a fixed  position  or on a 
trailer  or more  generally  on a vehicle  chassis;  
Insulating boom  
That portion  of an aerial  device  used for live work  that insulates  the competent persons’  
platform  from  earth  and from  which  a competent person  may work  safely  on live apparatus;  
Live part  
any conductive  part of apparatus,  which  is alive  and in normal  use, and includes  the neutral  
conductor;  
Live work  
 maintenance,  repair,  building  and construction  work  carried  out on live and operational  
apparatus  using  approved  techniques  and equipment  as specified  in this section,  and live 
working  has a similar  meaning;  PRD/ SZNS  077: 202 3 
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The competent person -carrying  component  of an aerial  device,  such as a bucket;  
Safe working clearance  
The minimum  distance  that must  be maintained  between  any parts  of the body  of a 
competent person,  or the conductive  tool directly  handled,  and live parts  at different  
potentials,  which  minimum  distance  is the sum of the electrical  distance  and ergonomic  
distance;  
Access  
Authorised  entry  into a restricted area,  prohibited  area,  live chamber  or on a power  system;  
 Access lock  
a lock that forms  part of a series  of locks  permitting  access  to prohibited  areas  or stations,  
which  can only be opened  with a master  key for the series  of locks;  
Additional  earth  
a registered  earth  or earthing  gear that may be applied  to a busbar  or a line; 
Alive 
electrically  charged,  and live has a similar  meaning;  
Apparatus   
any - 
1 electrical  equipment  such as generating  plant,  switch -gear,  transformer,  regulating  gear,  
busbar,  cluster -bar, feeder,  line, auxiliary  apparatus,  including  all associated  control  and 
protection  equipment,  operated  at different  voltages;  or 
2 any other  apparatus  installed  on a site, forming  part of a power  system;  
Approved  
approved  in writing  by a licensee;  
Authorised  
authorised  in writing  to perform  predefined  duties;  
Authorised  operation  
any work  executed  under  instruction  of the system operator ; 
Auto-reclose  (ARC)  
a preset  function  applied  on certain  breakers  or reclosers,  which  allows  automatic  reclosure  
of the breakers  or reclosers  after opening  on fault occurrences;  
 Auxiliary apparatus  
secondary  apparatus,  and includes  auxiliary  supply  or any supporting  apparatus  in a station  
for ensuring  the proper  function  of apparatus,  such as protection  schemes,  control  systems,  
communication  systems  and AC/DC  supplies;  
Barricade  
barrier,  and barricaded  has a similar  meaning;  
Barrier  
an approved  device  designed  to restrict  approach  to live apparatus;  
Basic insulation level  (BIL)  
specific  insulation  level,  expressed  in kilovolt  (kV),  to which  a power  system  is designed  
and constructed;  PRD/ SZNS  077: 202 3 
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all the apparatus  in the same  circuit  situated  in one or more  floors  in a building or through  a 
structure,  from  and including  the busbar  links;  
Breaker  
 a device  designed  to make,  carry  or break  electric  current  both under  normal  and fault 
conditions,  and recloser  has a similar  meaning;  
Busbar  
a conductor  or group  of conductors  that serves  as a common  connection  for two or more  
circuits  within  a station;  
Cable  
A feeder,  normally  underground,  and includes  the terminations;  
 Chamber  
an enclosure  in which  apparatus  is separated  from  other  apparatus  by partition  walls  or other  
means,  the access  to which  is restricted  by interlocks;  
Circuit  
the arrangement  of conductors  and apparatus  from  and including  the blades  of all links  or 
the contacts  of other  apparatus  provided  for completing  the connection  to the busbar;  
Circuit  breaker  
breaker;  
Close proximity  
 a position  in which  any body  part of a person  or tool being  used by a person  may 
inadvertently  breach  the minimum  safe working  clearance;  
Cluster -bar 
the central  connection  point,  mounted  on a pole at a point  below  a person’s  feet, where  all 
the clamps  of the portable  earths  between  the earth  spike  and the conductors  are connected;  
 Commissioning   
the pre-determined  sequence  of inspections,  tests and energising  procedures  designed  for the 
integration  of new apparatus  into a power  system;  
 Communication set  
 includes  a telephone,  cellular  phone,  radio  or any other  device  designed  for communication  
purposes;  
Connect  
 making a connection  or series  of connections  to obtain  electrical  continuity  in a circuit,  or 
between  apparatus,  or between  apparatus  and earth;  
 Conductor   
 any bar, pin, tube,  socket,  wire,  jumper,  dropper,  cable  or line used for conducting  
electricity,  which  is so arranged  to be connected  to a source  of electrical  potential;  
Consumption   
electricity  consumed  in kilowatt  hour (kWh);  
Control centre  
a place  from  where  the safe operation  of generation,  transmission   or distribution  of 
electricity  to customers  is controlled  or directed;  PRD/ SZNS  077: 202 3 
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All rights reserved  Control panel  
the panel  on which  auxiliary  apparatus  are mounted,  such as control  switches,  protective  
relays,  measurement  devices  or other  equipment  to control,  measure  and protect  apparatus,  
and includes  a protection  panel,  an interface  panel,  a supplementary  panel,  a mimic  panel,  a 
metering  panel  and an alarm  panel;  
 Control switch  
a switch  provided  for controlling  the operation  and function  of apparatus  and auxiliary  
apparatus;  
Danger  
 a risk of loss of human  life, bodily  injury  or damage  to health  from  electric  shock,  burn or 
any hazardous  condition,  or loss of or damage  to apparatus,  arising  from  the provision  or 
use of electricity;  
 Dead 
 any apparatus  so described  is at or about  zero potential  and disconnected  or isolated  from  
all possible  sources  of electrical  potential  or any live power  system ; 
De-energised   
the apparatus  is not electrically  connected  to a live power  system  and has not been  
discharged,  isolated,  safety  tested  or earthed;  
 Discharged   
 1 connected  to earth  and that the apparatus  is free of any residual  or induced  electrical  
potential;  and 
2 stored  energy  has been  released,  such as a closing  spring  in a breaker,  hydraulic,  
pneumatic  or gas pressure  in a system,  or energy  stored  in a battery  or capacitor  bank;  
 Disconnected  
apparatus  is not connected  to a source  of electrical  potential  achieved  by the removal  of a 
connection  or series  of connections  thereby interrupting  or breaking  electrical  continuity  in 
a circuit,  or between  apparatus,  or between  apparatus  and earth,  but may still have  to be 
discharged;  
Distribution  
the conveyance  of electricity  through  a distribution  system,  which  consists  wholly  or mainly  
of medium  and low voltage  networks,  to a customer;  
 Distribution system  
 the network  of stations,  transformers,  lines  and cables  whereby  electricity  is distributed  to a 
customer;  
 Double circuit structure  
a structure  supporting  two circuits  of the same  voltage  on the same  structure  but situated  on 
opposite  sides  of the centre  of the structure;  
Dropper   
a conductor  installed  to connect  apparatus  to a line or a busbar;  
 Drop out fuse   
 a single -phase  pole mounted  outdoor  air insulated  mechanically  operated  device  charged  
with a fuse for protecting  apparatus  in the event  of a fault occurrence;  
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All rights reserved  Earth - 
1 as a noun,  means  the general  mass  of the earth  and is regarded  to be at zero potential;  
2 as a verb,  means  applying  earthing  gear or connecting  apparatus  to earth  in a manner  that 
will ensure  an immediate  safe discharge  of electrical  energy  at all times;  
 Earth mat  
 the subterranean  conductive  material  installed  in a station,  at a structure  or on a transformer,  
pylon  or pole or under  a line to ensure  that a connection  can be made  between  apparatus  and 
earth;  
Earthing gear  
the fixed  or portable  earthing  devices,  such as earthing  links/  switches  or portable  earths,  
used for earthing  apparatus;  
Earthing link/switch  
earthing  gear,  mechanically  or electrically  operated,  permanently  connected  at one point  to 
the earth  mat and designed  to earth  apparatus;  
Earth spike   
a copper  clad steel rod, of adequate  current  carrying  capacity,  which  is driven  into the ground  
to ensure  that an electrical  connection  is made  between  apparatus  and earth;  
Electric fence  
a fence  on which  an electric  fence  energiser  is connected  to deliver  a periodic  non lethal  
amount  of electricity  to the fence  to prevent  unauthorised  access  to certain  areas;  
Electrical connection  
 the permanent  or temporary  connection  between  apparatus  or apparatus  and earth  thus 
providing  a continuous  path whereby  any form  of electrical  energy,  charge  or current  flow 
can be conducted  safely;  
 Electricity Act  
 The Electricity  Act, 2007  (Act No. 3 of 2007),  as amended  or substituted;  
Emergency  
A situation  where  danger  can only be avoided  by immediate  action;  
Emergency switching  
the opening  only of such breaker,  recloser,  switch  or similar  device  as may be necessary  to 
avoid  danger;  
 Enclosure  
any room,  chamber,  yard or enclosed  area in which  it is possible  for a person  from  
ground/floor  level  to make  inadvertent  contact  with,  or come  into close  proximity  of live 
conductors  or apparatus;  
 Energised  
apparatus  is connected  to a live power  system  and is in service;  
Export   
 the provision  of electricity  to customers  inside and or outside  the physical  borders  of 
Eswatini;  
Factor of safety  
 the ratio of a component’s  failing  load to the maximum  working  load for which  it has been  
designed;  PRD/ SZNS  077: 202 3 
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All rights reserved  Fault 
an unplanned  occurrence  or defect  in an item which  may result  in one or more  failures  of 
the item itself  or of associated  apparatus;  
Feeder   
a bay, a power  line or a cable,  whether  underground  or not - 
1 in or from  a  station;  or 
2 between  two or more  stations;  or 
3 from  a station  to a customer,  and includes  all structures,  supports,  conductors  and related  
hardware;  
Footing resistance  
the resistance  between  a structure  and earth;  
Frequency   
 the cyclic  frequency  of a sinusoidal  waveform  over a period  of one second  (cycles/second),  
expressed  in Hertz  (Hz);  
Generation  
 the production  of electricity  by way of natural  or artificial  processes;  
Generating plant  
apparatus  designed  for the purpose  of generating  electricity  and includes  all support  
apparatus;  
Ground/floor level  
the general  surface  a person  walks  on, including   a structure  or apparatus  plinth   other  
than a structure  or apparatus  plinth  that has been  constructed  to obtain  safeworking  
clearance  or safe ground  clearance;  
 Hand back  
the transfer  of responsibility  for apparatus,  as specified  in the hand  out, by a responsible 
person  to the system  controller,  detailing  all work  performed  and thereby  authorising  the 
safe return  of the apparatus  to service;  
 Hand out   
 the transfer  of responsibility  for specific  apparatus  by the system  controller  to an appointed  
operator  or authorised  person,  whereby  the appointed  operator  or authorised  person  is 
authorised  to work  safely  on the apparatus;  
Hand over  
 the detailed  confirmation  by an appointed  operator,  authorised  person  or responsible  person  
to the system  controller  that new or refurbished  apparatus  is ready  to be commissioned  and 
placed  in service  whereby  such apparatus  will become  the responsibility  of the system  
controller;  
Health and Safety Regulations  
 The Regulations  relating  to the Health  and Safety  of Employees  at Work,  1997,as  amended  
or substituted;  
High voltage  
 a voltage  of more  than 33 000 volt (RMS);  
Human machine interface  (HMI)  
 a computer,  normally  in a station  or control  centre  - PRD/ SZNS  077: 202 3 
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All rights reserved  1on which  is displayed  the layout  and operational  state of apparatus  in a station  or a power  
system;  and 
2 which  records  events  and allows  remote  monitoring  and operation  of certain  apparatus;  
Import   
 The supply  of electricity  to Eswatini  from  electricity  providers,  independent  power  
producers  or power  utilities  inside and/or outside  the physical  borders  of Eswatini;  
Incident  
a work -related  detrimental  occurrence;  
in commission  
apparatus  is available  for immediate  use, although  it may not actually  be in service;  
Induction  
the electrical  charge  produced  in a conductor  due to the variation  of a magnetic  field in its 
vicinity,  such as in adjacent  circuits  and static  charge  build  up due to weather  conditions;  
 in service  
apparatus  is energised  and in use; 
 Insulated  
covered,  enclosed,  surrounded  or apparatus  supported  with insulating  material  of such 
thickness  and properties  that it will prevent  the flow of electrical  energy  or potential  between  
the object  so covered  and its surroundings  or any external  object  in contact  with it, including  
the prevention  of making  contact  with earth;  
Insulating material  
any non-conductive  material  such as glass,  porcelain  or other  composite  material  used for 
covering,  enclosing,  surrounding  or supporting  apparatus  or part thereof;  
 Insulator  
device  made  from  insulating  material  designed  to - 
1 obtain  the required  basic  insulation  level;  and 
2 prevent  electrical  contact  between  a live part and its surroundings;  
Interlock  
A mechanism,  whether  operated  mechanically,  electrically,  electronically,  computer  
software  driven  or any combination  thereof,  designed  to ensure  the safe execution  of a 
predetermined  sequence  of operations;  
interlocking lock  
 a series  of locks  in a station  for which  only one specific  key exists  to perform  safe operations  
on an interlocking  system;  
in writing  
 hand  written,  typed  or printed,  duly signed  and dated,  and includes  a transmission  to the 
intended  recipient  concerned  by means  of facsimile  or electronic  mail;   
Note: to include modern technology  
 Isolate  
disconnecting  apparatus  from  all possible  sources  of electrical  potential  to create  a visible  
gap between  a live part and a de-energised  part, which  may be obtained  by - 
1 opening  or removing  fuses  or drop out fuses;  
2 opening  links,  isolators  or disconnectors;  PRD/ SZNS  077: 202 3 
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All rights reserved  3 removing  droppers  or jumpers;  
4 opening  air break  switches;  
5 withdrawing  truck -type switch  gear;  
6 immobilising  breakers  having  visible  contact  separation,  and not fitted  with grading  
capacitors;   
7 utilising  an approved  changeover  breaker,  switch,  link or similar  device  with mechanical  
interlock,  and if contact  separation  is not visible  due to design  or physical  construction  
criteria,  isolation  is deemed  not to have  been  achieved  unless  a combination  of at least two 
of the following  displays  indicate  simultaneously  that contact  separation  has indeed  taken  
place:  
i. External  mechanical  indicator;  
ii. Electro -mechanical  indicator;  
iii. Electrical -operated  position  indicator;  
iv. Electronic  display  by HMI  or bay controller;  
 Isolator  
a device  provided  for the purpose  of isolating  apparatus  from  the source  of supply;  
Jumper  
a conductor  installed  between  various  apparatus  to create  continuity;  
Key 
 a key or an electric,  electronic,  computer  software  driven  or other  device  used in a station  to 
operate  locks;  
 Kilowatt -hour  (kWh)  
 the consumption  of electrical  energy  equivalent  to one kilowatt  of power  sustained  for 
one hour;  
 Labour Act   
the Labour  Act, 2007  (Act No. 11 of 2007),  as amended  or substituted,  and includes  the 
Health  and Safety  Regulations;  
 Line  
an overhead  feeder  consisting  of conductors,  supports  and related  hardware  between  power  
stations,  sub-stations  and customers;  
 Link 
a device,  such as an isolator,  disconnector  or similar  disconnecting  device,  for making  or 
breaking  a circuit  when  no load current  is flowing;  
Linking   
the opening  or closing  of a link, isolator,  disconnector  or similar  disconnecting  device  when  
no load current  is flowing;  
Live chamber   
 any chamber  in which  inadvertent  human  contact  with conductors  or live parts  of apparatus  
working  at Low voltage to  high voltage  is possible  from  ground/floor  level;  
Live part  
any conductive  part of apparatus,  which  is alive  and in normal  use, and includes  the neutral  
conductor;  
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All rights reserved   Load current  
the current  flowing  in a circuit  that is associated  with electricity  consumption;  
Loading    
the matching  of electricity  generation  and demand  of a power  system;  
Local control centre  
a temporary  location  from  where  safe operations  on a pre-defined  section  of a power  system  
may be controlled  or directed  in accordance  with of this Standard;   
Lock 
 includes  an access  lock,  an interlocking  lock,  a marriage  lock,  an operating  lock,  a safety  
lock,  a servitude  lock and a unique  lock;  
low voltage  
a voltage  of 1000  volt (RMS)  or less; 
Made safe 
de-energised,  isolated  and earthed  as required  to allow  the necessary  work  to be carried  out 
without  danger;  
 Marriage lock   
 a lock placed  in series  with another  lock allowing  various  persons  to have  access  to 
servitudes  and premises,  and marriage  locking  has a similar  meaning;  
Medium voltage  
 a voltage  of more  than 1 000 volt (RMS)  but not more  than 33000 volt (RMS);  
Operating  
switching,  linking,  safety  testing  and earthing  operations  in that specifi c order;  
 Operating diagram/mimic  
the permanent  single  line diagram  in a control  centre  or station  indicating  the operating  
position  and operational  state of all apparatus;  
Operating lock   
 a lock forming  part of a series  of locks,  operated  by a master  key that gives  access  to live 
chambers  and to certain  apparatus  only for exclusive  safe operations  by an appointed  
operator;  
Operating procedures   
 approved  detailed  sequences  for ensuring  the safe operating  of a power  system,  or part 
thereof,  which  are developed  and maintained  by the responsible  official;  
Operating  stick  
an approved  insulated  rod or telescopic  tube to - 
i.  enable  links  and fuses  to be operated;  or 
ii. carry  out safety  testing  and earthing  operations;  
Operation  
 the safe execution  of a task, instruction,  procedure  and guideline  in terms  of this Standard,  
and includes  the general  functions  of system  operations;  
Out of commission  
 apparatus  taken  out of service  and not available  for immediate  use; 
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All rights reserved  Out of service  
 apparatus  connected  to a power  system  but not presently  in use; 
Dual line  system   
a system  where  more  than one circuit  of different  voltages  are supported  on the same  
structure,  excluding  any double  circuit  structure  and high voltage  structure  carrying  low 
voltage  conductors;  
Point of supply  
 any point  where  a power  system  or a section  of a power  system  can be made  alive;  
Portable earth   
 a mobile  flexible  earthing  gear,  which  may be used as a registered  earth,  working  earth,  
additional  earth  or any other  safe earthing  application  as may be required,  and portable  
earthing  gear  has a similar  meaning;  
Power line   
 an electric  line whose  conductors  are supported  above  ground,  generally  by means  of 
insulators  and appropriate  supports  erected  to convey  electricity  for any other  purpose  than 
communication,  but excluding  the overhead  contact  or catenary  conductors  of an electric  
traction  system,  and overhead  line has a similar  meaning;  
Power station  
 a site on which  electricity  is generated;  
Power station control room  
 the permanent  location  at a power  station  from  where  the safe operations  of the power  station  
is controlled  or directed;  
Power system  
 the interconnected  system  comprising  powe r stations,  feeders,  stations  and apparatus  used 
in connection  with the generation,  transmission,  distribution  and supply  of electricity;  
Prohibited area  
 a normally  enclosed  area in which  live conductors  or live parts  of apparatus  are accessible,  
but situated  in such a position  that inadvertent  human  contact  there  with is not possible;  
Registered earth  
 any earthing  gear applied  or removed  on instruction  from  a system  controller;  
Remote control  
 the operation  or operating  of apparatus  from  a place  not immediately  adjacent  to the related  
apparatus;  
Restricted area  
 an area other  than a live chamber  or a prohibited  area,  which  is enclosed  for the purpose  of 
power  system  security  and the safety  of persons;  
Safe working clearance  
 the minimum  safe distance  to be observed  between  - 
i. different  live parts  of apparatus;  or  
ii. live parts  of apparatus  and earth,  to prevent  a short -circuit  or inadvertent  human  
contact  with such live parts;  
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All rights reserved  Safety lock  
a lock used for safe operations  in a power  station  for which  - 
1 only one specific key is in use; and 
2 a master  key may be used under  extreme  circumstances  to override  the specific  safety  
lock;  
Safety panel   
 apparatus  or a line that has been  isolated  and earthed  as a precautionary  measure  to prevent  
contact  with the live high voltage  apparatus  or line where  there  is a risk of encroaching  in 
person  or with machinery  or objects  on the safe working  clearance  when  work  is being  
performed  near or close  to such apparatus  or line; 
Safety testing   
 the testing  of apparatus  to ascertain  whether  it is alive  or dead  by means  of approved  test 
equipment  provided  for this purpose;  
Sectionaliser  
 a switch  intended  to open  automatically  to disconnect  part of a power  system,  during  the 
open  time of a recloser  or breaker,  which  has tripped,  to clear  a fault ; 
Servitude lock   
 a lock forming  part of a series  of locks  to gain access  to line servitudes  and is operated  by a 
master  key; 
Shutter   
 a mechanically  operated  safety  cover  for or on an orifice  to prevent  access  to live parts  of 
switch  gear;  
Single -line diagram  
 a diagram  depicting  the layout  equivalent  single  line symbols;  
Source of supply  
portion  of a power  system  from  which  the apparatus  can be made  alive;  
Special operating procedures   
 an approved  sequence  for ensuring  the safe operating  of apparatus  at identified  stations,  
which  are developed  and maintained  by the responsible  official;  
Station   
 a power  station,  transmission  station,  distribution  station,  switching  station,  isolating  station,  
mobile  station  or other  station  or substation  with apparatus  maintaining,  controlling,  
supporting  or forming  part of a power  system,  and may contain  generating  plant,  
transformers  or switching  or linking  apparatus;  
Stay 
 a steel wire,  rope,  rod, pole  or other  device  that supports  a pole or structure;  
Supervision  
 overseeing  the actions  of a person  to prevent  any danger  or contravention  of this Standard;  
Supply  
 the delivery  of electricity  to a customer  as a commodity;  
Supply poi nt 
the point  at which  electricity  is received  by a customer;  
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All rights reserved  Switch   
 a device,  other  than a breaker,  designed  for making  and breaking  a rated  flow of electric  
current,  and includes  an air-break  switch,  a spring -operated  link, a weight  operated  
disconnector,  a load break  link, a transrupter  or any similar  device;  
Switching  
 the opening  and closing  of a breaker,  recloser,  sectionaliser,  switch  or similar  apparatus,  and 
includes  operating  auxiliary  apparatus;  
Trading  
 the wholesale  or retail  buying  and selling  of electricity;  
Transmission  
the conveyance  of electricity  by means  of a transmission  system,  which  consists  wholly  
or mainly  of high voltage  networks  and electrical  plant,  from  an energy  source  or system  
to a customer;  
Transmission line  
an overhead  power  line operating  at high voltage  to transfer  large  amounts  of electricity;  
Transmission system   
 the network  of stations,  transformers,  feeders,  lines,  cables  and other  apparatus  whereby  
electricity  is transmitted;  
 Trip 
 the opening  only of a breaker,  recloser,  switch  or similar  device  activated  by means  of 
installed  protection  on occurrence  of a fault on apparatus;  
Underground cable  
 an electric  line with insulated  conductors  buried  directly  in the ground,  or laid in cable  ducts,  
trenches,  pipes  or troughs;  
 Unique lock   
 a dedicated  lock for which  only one key exists,  to isolate  and lock apparatus  or a customer  
supply  point  from  a power  system  to ensure  safe separated  operations;  
Voltage  
the electric  potential  between  two points  that gives  rise to the flow of electricity  and where  
specified,  the RMS  value  of the voltage;  
Work  
All physical  activities  in connection  with apparatus,   excluding  operating  and other  non-
dangerous  activities,  which  will not affect  the health  and safety  of persons  or the safe 
operation  of apparatus;  
 Working earth  
the visible,  supplementary,  portable  earthing  gear applied  on all sides  and as close  as 
possible  to the point  of work;  
Workplace  
the place  where  physical  work  is done  on a power  system.  
 
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All rights reserved  3.3 Printed Forms, Books and Notices  
In this Standard,  including  its introduction,  unless  the context  otherwise  indicates  - 
Authority  
 A letter  of authority  signed  by the responsible  official,  stipulating  the level  of authority  and 
responsibilities  with regard  to operations,  services,  access  to prohibited  areas  or live 
chambers  or live work  on a power  system,  which  letter  of authority  - 
i. may extend  to all voltage  levels  from  the point  of generation  up to a supply  point;  
ii. is valid  for the maximum  period  specified  by a licensee;  
iii. may be cancelled,  altered  or withdrawn  at the discretion  of the licensee  at any time due 
to any misconduct,  resignation,  transfer  or operational  change;  
Control  panel label/tag  
 a notice  displayed  on a control  panel  in a station  indicating  that apparatus  is being  worked  
on and may indicate  the position  of earthing  gear;  
 Indemnity form  
a form  that must  be completed  by all persons  as required  by the licensee;  
Licence  
a licence  for the generation,  transmission,  trading,  distribution,  supply,  import  or export  of 
electricity,  issued  in terms  of the Electricity  Act; 
Logbook   
a book  provided  for keeping  a record  of all events,  incidents,  operations,  operation  counter  
readings  and related  activities,  which  is accessible  at all times;  
Operating drawing  
a single  line diagram  that depicts  the layout  of a power  system,  station  and lines  between  
stations  and customers  for the issuing  and execution  of operating  instructions;  
Operating instruction form  (OIF)  
the printed  form  used for recording  instructions  issued  by a system  controller  to an appointed  
operator  or authorised  person  relating  to the operations  to be carried  out on apparatus;  
 Record   
any recording  system,  book,  form  or statement,  whether  printed  or not, to keep  all 
information  and its daily  activities  up to date;  
Warning notice  
a notice  provided  - 
1 to indicate  and warn  that work  is in progress  on apparatus;  or 
2 to indicate  any special  operating  condition  in force;  
Work permit  
a document  permitting  work  to be carried  out on specific  apparatus,  which  has been  prepared  
in accordance  with this Standard  so that the intended  work  may be carried  out with safety;  
Work permit form  
the printed  form  containing  the application,  permit,  clearance  and worker’s  declaration  for 
the authorisation  of work  to be done  on apparatus  in accordance  with this Standard;  
 
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All rights reserved   Worker’s declaration  
a declaration  signed  by the appointed  operator,  the responsible  person  and the worker  
concerned,  confirming  - 
1 that apparatus  to be worked  on was made  safe;  and 
2 an understanding  of the restrictions  and details  of the work  to be carried  out; 
Workers register  
a register  of workers  assigned  to do work,  which  is completed  by an authorised  person  or a 
responsible  person.  
Live work declaration form  
 A printed  form  containing  declaration  and clearance  sections  for the authorisation  of all live 
work  to be done  on live, operational  apparatus  in terms  of this Standard;  
Live work warning notice  
Any portable  warning  notice  provided  to indicate  that live work  is in progress  on apparatus  
and to indicate  any special  operating  condition  in force  on any panel  or circuit  while  live 
work  is in progress.  
4 Control of a Power System    
4.1 Duties and Responsibilities of a System Controller  
4.1.1 The system  controller  shall  be responsible  for the overall  control  of a power  system  
and in addition  to any other  duties  or responsibilities  specified  elsewhere  in this Standard  
and Electricity Act , and any other relevant technical standards and codes  for carrying  out 
the following  duties:  
Note: Include other relevant codes and standards and check alignment  
4.1.1. 1 Ensuring  the safety  of human  life, safety  of equipment  and the continuity  of power  
supply  to customers,  in that order  of priority;  
4.1.1. 2 issuing  instructions  for the loading  of generating  plant  and the control  of frequency  
and voltage  of the power  system  under  his or her control;  
4.1.1. 3 issuing  instructions  as set out in the special  operating  procedures;  
4.1.1.4  issuing  instructions  for safe operations  on the power  system  under  his or her 
control.  
4.1.2 The following  operations  are regarded  as exceptions  and are not executed  under  direct  
instructions  from  the system  controller:  
4.1.2. 1Emergency  switching;  
4.1.2. 2 working  earths  on apparatus;  
4.1.2. 3 operating  on auxiliary  apparatus  in stations  below  1 000 volts (RMS);  
4.1.2. 4 operating  via supervisory  remote  control  performed  by a system  controller;  
4.1.2. 5 operating  under  the jurisdiction  of an established  local  control  centre.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.1.3 Before  issuing  any operating  instruction  to an appointed  operator  or authorised  person,  
the system  controller  shall  ensure  that all parties  have  corresponding  updated  operating  
drawings  in their possession.  
4.1.4 The system  controller  shall  keep  a record  of - 
4.1.4. 1 the times  and details  of all operating  carried  out by the system  controller  or under  
his or her instructions;  and 
4.1.4. 2 the names  of the persons  instructed  to carry  out the operating , and shall  record  and 
act upon  all alarms  that may appear  as a result  of such operating.  
4.1.5 The system  controller  shall  keep  a record  of - 
4.1.5. 1the times  and details  of all emergency  switching;  and 
4.1.5. 2 the names  of the persons  who have  carried  out the emergency  switching,  and shall  
record  and act upon  all alarms  that may appear  as a result  of such emergency  switching.  
4.1.6 The system  controller  shall  - 
4.1.6. 1 update  the operating  diagram/mimic  in the control  centre  in such a way as to indicate  
at all times  the operational  state of breakers,  switches  and links  and the position  of earths  
throughout  the section  of the power  system  under  his or her control;  and 
4.1.6. 2 keep  a record  of the names  of the appointed  operators  to whom  apparatus  are handed  
out. 
4.1.7 Switching  of auxiliary  apparatus  or any work  carried  out on auxiliary  circuits  by an 
authorised  person  shall  be confirmed  with the system  controller  and the hand  out and hand  
back  procedures  shall  be followed.  
4.1.8 The system  controller  shall  give to the relieving  system  controller,  for the proper  
discharge  of his or her duties  - 
4.1.8. 1 all the required  information  as to the state of the power  system  under  his or her 
control;  and 
4.1.8. 2 any other  information  that may be necessary,  
4.1.9 The relieving  system  controller  shall  obtain  this information  from  the system  controller  
and read the relevant  entries  in the records.  
4.2 Keeping of Records  
4.2.1 Operating records  
4.2.1. 1A record  shall  be maintained  in the control  centre  of- 
4.2.1. 1.1 the names  and contact  details  of all appointed  operators,  authorised  persons  and 
responsible  persons,  together  with the extent  of their authorisation;  and 
4.2.1. 1.2 permanent  and temporary  settings  of all relays  and protective  gear.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.2.1. 2 Logbook  
4.2.1. 2.1 The licensee  shall  provide  a logbook  at each station  in which  the appointed  
operator,  the authorised  person  and the responsible  person  shall  record  all operating  or work  
carried  out on a power  system.  
4.2.1. 2.2 All operating  performed  by an appointed  operator  must  be written  down  on an 
operating  instruction  form,  including  the procedures  for apparatus  hand  over,  hand  out and 
hand  back,  which  procedures  shall  also be recorded  in the logbook.  
4.2.1. 2.3 All switching  operations  performed  on auxiliary  apparatus  by an authorised  person  
must  be written  down  on an operating  instruction  form,  including  the procedures  for 
apparatus  hand  over,  hand  out and hand  back,  which  procedures  shall  also be recorded  in 
the logbook.  
4.2.1. 2.4 Every  entry  relating  to the application  of earthing  devices  shall  state the location  
in the circuit  where  each earthing  device  is applied.  
4.3 Issue and Receipt of Operating Instructions and the Use of 
Operating Instruction Forms  
4.3.1 Permission to operate  
4.3.1. 1 No person  shall  carry  out any operating  or operation  on a power  system  without  the 
prior  authorisation  by the system  controller,  except  in cases  as stipulated  in paragraph  4.1.2 
of this Standard.  
4.3.1. 2 Issue  and receipt  of operating  instructions .  
4.3.1. 2.1 All instructions  from  the system  controller  to an appointed  operator  or authorised  
person  relating  to operating  or operation  of apparatus  shall  be given  in detail  and 
sequentially  without  abbreviation,  stating   
4.3.1.2. 1 the date;  
4.3.1.2. 2 the name  of the station;  
4.3.1.2. 3 the apparatus  to be worked  on; 
4.3.1.2. 4 the nature  of the operation  to be carried  out; 
4.3.1.2. 5 the time of receiving  and completion  of the instruction;  and 
4.3.1.2. 6 the signature  and printed  name  of the appointed  operator  or authorised  person.  
4.3.1. 2.2.1  Each  separate  step in the instruction  shall  be written  on a new line on the 
operating  instruction  form.  
4.3.1. 2.2.2  Operating  instructions  for switching  and linking  may be written  on the same  
operating  instruction  form  and in that order.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.3.1. 2.2.3  Safety  testing  and earthing  instructions  must  be written  on a separate  operating  
instruction  form.  
4.3.1. 2.3.1  The instructions  must  be read back  by the appointed  operator  or authorised  
person  to the system  controller,  who shall  confirm  or, if necessary,  correct  the instructions.  
4.3.1. 2.3.2  If both parties  agree  that the execution  of the instructions  can be performed  
safely,  the operating  instruction  form  reference  number  must  be given  to the system  
controller  and the instructions  confirmed  with the issue  of a time,  which  must  be noted  as 
the time received  for commencement.  
4.3.1. 2.3.3  The form  must  then be signed  by the appointed  operator  or authorised  person.  
4.3.1. 2.4.1  The instructions  may be pre-written  on the operating  instruction  form  by the 
appointed  operator  or authorised  person  doing  the operating,  or person  authorised  to transmit  
operating  instructions.  
4.3.1. 2.4.2  If the instructions  have  been  incorrectly  pre-written,  they must  be cancelled  and 
rewritten  completely  on a new operating  instruction  form  under  instruction  from  the system  
controller.  
4.3.1. 2.5 A copy  of the operating  instruction  form  shall  remain  adjacent  to the 
communication  set until completion  of the operating  detailed  on it. 
4.3.1. 2.6.1  The original  of the operating  instruction  form  shall  be taken  to the place  where  
the operating  is to be carried  out. 
4.3.1. 2.6.2  The instructions  shall  be read by the appointed  operator  or authorised  person  
carrying  out the operating,  who shall  verify  that the apparatus  and the intended  operating  
correspond  with the written  instruction  before  the operating  detailed  on the operating  
instruction  form  is commenced.  
4.3.1. 2.7 Each  instruction  on the operating  instruction  form  shall  be carried  out in its entirety  
without  undue  delay  and each item as detailed  on the operating  instruction  form  shall  be 
ticked  off as each step of operating  is completed.  
4.3.1. 2.8.1  When  a person  is being  trained,  both the appointed  operator  or authorised  person  
and the trainee  shall  satisfy  themselves  that the apparatus  and intended  operating  correspond  
with the instruction  as received  from  the system  controller  before  the operating  is 
commenced.  
4.3.1. 2.8.2  The operating  instruction  form  shall  be signed  by the trainee  and countersigned  
by the appointed  operator  or authorised  person.  
4.3.1. 2.8.3  No operating  instructions  shall  be issued  by one trainee  to another  trainee.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.3.1. 2.9 In the event  of an unforeseen  delay  in the execution  of the instructions  in their 
entirety,  the operating  must  be terminated  and the cause  reported  to the system  controller  
where  upon  the existing  instructions  must  be cancelled  and new instructions  issued.  
4.3.2 Report back on completed operating   
4.3.2.1 The system  controller  shall  be informed  as soon  as possible  after an operating  
instruction  has been  completed.  
4.3.2.2 Report  back  on completed  operating  shall  be given  in full to the system  controller  by 
the appointed  operator  or authorised  person  and all details  logged  accordingly.  
4.3.2.3 The system  controller  shall  then issue  the completion  time to the appointed  operator  
or authorised  person.  
4.3.2.4 The original  operating  instruction  form  relating  to a completed  operating  shall  be 
retained  for a minimum  period  of six months  at the location  determined  by the licensee.  
4.3.2.5 Each  completed  operating  instruction  book  containing  the copies  of operating  
instruction  forms  must  be archived  for a period  of five years,  where  after it may be destroyed  
if no query  has arisen  regarding  any entries  during  that time.  
4.4 Relay of operating instructions through a third person  
4.4.1 Where  operations  are required  on a power  system  in the absence  of direct  
communication  between  the system  controller  and the appointed  operator  or authorised  
person,  the related  operating  instructions  may be relayed  through  a third  person,  in which  
case the third  person  shall  relay  the precise  operating  instructions  and in doing  so, comply  
under  the guidance  of the system  controller  with the relevant  requirements  specified  in this 
Standard.    
4.4.2 When a system controller  gives authority for switching  to be carried out, they shall  
communicate directly with the responsible person  who is to carry out the switching.  Where, 
for special reasons, direct communication is not possible, licensee approved  procedure shall 
be followed.  
4.5 Issue and receipt of pre -authorised instructions  
4.5.1 In the event  of poor or no communication  between  the system  controller  and the 
appointed  operator  or authorised  person  when  operating  is required  on a power  system  and 
the relay  of operating  instructions  by a third  person  is not practicable,  pre-authorised  
operating  instructions  may be issued.  
4.5.2.1  Pre-authorised  operating  instructions  may only be issued  on the day that the 
operating  takes  place.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.5.2.2  The system  controller  and the appointed  operator  or authorised  person  may discuss  
and pre-write  the instructions  beforehand.  
4.5.2.3  The pre-authorised  instructions  shall  only enter  into force  once  the system  controller  
has authorised  the instructions  by issuing  a commencement  time.  
4.5.3.1  Pre-authorised  operating  instructions  to an appointed  operator  shall  be issued  for the 
switching,  linking,  safety  testing,  earthing  or work  to be performed  and upon  completion,  
the sequential  restoration  of apparatus  to service.  
4.5.3.2  All operations  and detail  of the work  performed  shall  be reported  to the system  
controller  as soon  as possible  where  upon  the system  controller  shall  issue  a completion  
time.  
4.5.4.1  Pre-authorised  operating  instructions  to an authorised  person  shall  be issued  for the 
switching  or work  to be performed  and upon  completion,  the sequential  restoration  of 
apparatus  to service.  
4.5.4.2  All operations  and detail  of the work  performed  shall  be reported  to the system  
controller  as soon  as possible  whereupon  the system  controller  shall  issue  a completion  time.  
4.5.5.1  In the event  of loss of supply  due to a trip to multiple  customers  on a feeder  with 
only one source  of supply,  a pre-authorised  operating  instruction  may be issued  to an 
appointed  operator.  
4.5.5.2  The pre-authorised  operating  instruction  shall  apply  to the affected  feeder  only.  
4.5.5.3  Additional  appointed  operators  may assist  under  instruction  of the appointed  
operator  in charge  to restore  the supply.  
4.5.5.4  The pre-authorised  operating  instruction  includes  permission  to operate  the feeder  
breaker,  other  switch  gear or links  in the same  circuit  as required.  
4.5.6.1  In the event  of loss of supply  to a single  customer  with only one source  of supply,  a 
pre-authorised  operating  instruction  may be issued  to an appointed  operator  to restore  the 
supply.  
4.5.6.2  The pre-authorised  operating  instruction  shall  apply  to the affected  customer  supply  
point  only as from  the transformer  drop out fuses  to the customer.  
4.6 Circumstances when an operating instruction shall be cancelled  
4.6.1 Should  the safety  of persons  or apparatus  be in danger  during  the execution  of any 
operating  instruction  in circumstances  other  than those  indicated  in paragraphs  4.3.1. 2.4.1  
and 4.3.1. 2.4.2  and 4.3.1. 2.9 of this Standard,  all operations  must  be terminated  immediately  
and the operating  instruction  cancelled  either  by the system  controller  or the appointed  
operator  or authorised  person,  who detected  the danger.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.6.2 The system  controller  shall  then determine  the further  actions.  
4.7 Control of Loading of Power Stations Under Normal and 
Abnormal Conditions  
4.7.1.1 The system  controller  and the power  station  control  room  official  shall  liaise  closely  
regarding  all events  and conditions  that may affect  the loading  of the generating  plant  and 
continuity  of supply.  
4.7.1.2 The system  controller  shall  keep  the power  station  control  room  official  fully  
informed  as to the probable  demand  which  will be made  on the generating  plant  in the power  
station  and the capacity  of such generating  plant,  which  is required  to be in reserve  to ensure  
that the obligation  of supply  and demand  are met. 
4.7.2.1 The power  station  control  room  official  shall  notify  the system  controller  regularly  
as to the condition  of the generating  plant.  
4.7.2.2 Any change,  which  may affect  loading  arrangements  previously  made,  shall  be 
reported  to the system  controller  immediately.  
4.7.3.1 In the event  of conditions  arising  which  may affect  the safety  of the generating  plant,  
the power  station  control  room  official  shall  be solely  responsible  for so handling  and 
loading  each portion  of such generating  plant  to ensure  its safety  and shall  immediately  take 
corrective  action.  
4.7.3.2 The system  controller  must  be notified,  as soon  as possible,  of any change  during  the 
event  and new arrangements  shall  be made  for the loading  of such generating  plant.  
4.7.4.1 For work  on generating  plant,  the power  station  control  room  official  shall  make  the 
necessary  arrangements  with the system  controller  for the generating  plant  to be taken  out 
of commission.  
4.7.4.2 On completion  of the work,  the power  station  control  room  official  shall  notify  the 
system  controller  that the generating  plant  is available  for service.  
4.7.4.3 Should  any delay  arise  in returning  the generating  plant  to service  as pre-arranged,  
the power  station  control  room  official  shall  immediately  advise  the system  controller  of the 
delay  so that alternative  arrangements  may be made.  
4.7.5 Generating  plant  shall  be deemed  to be - 
4.7.5.1 out of commission  immediately  after the system  controller  has given  permission  for 
work  to be commenced  thereon;  
4.7.5.2 in commission  as soon  as the system  controller  has been  advised  that such generating  
plant  is available  for service.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.7.6.1 Should  abnormal  conditions  arise  requiring  deviation  from  any pre-arranged  work  
programme,  all parties  concerned  shall  adjust  to the altered  conditions  in the most  efficient  
and expeditious  manner.  
4.7.6.2 Any alternative  arrangements  shall  be reported  to the system  controller  and all parties  
concerned  shall  be informed  of the alternative  arrangements.  
4.8 Control and Loading of Transmission and Distribution Apparatus  
4.8.1 Subject  to paragraph  4.1 of this Standard,  the appointed  operator  or authorised  person  
shall  be responsible  for appara tus in service  and the loading  thereof  at each station.  
4.8.2 Whenever  apparatus  has to be taken  out of commission  for whatever  reason,  the 
appointed  operator  or authorised  person  shall  make  arrangements  with the system  controller  
and the customers  beforehand,  where  applicable,  to prevent  overloading  of apparatus  
remaining  in service.  
4.8.3 In an emergency,  the system  controller  shall  take the required  action  and where  
necessary,  in consultation  with the appointed  operator  or authorised  person  at the station  and 
shall,  as soon  as possible,  notify  the relevant  senior  officials.  
4.9 Order of Precedence in Use of Communication System  
All calls or messages  in connection  with the operation  of a power  system,  to and from  the 
system  controller,  appointed  operator,  authorised  person  or power  station  control  room  
official  on any communication  system  shall  at all times  be given  preference  by the system  
controller  over all other  calls or messages.  
4.10 Commissioning of Apparatus on First Installation or After 
Alteration or Repair  
4.10.1 No apparatus  shall  be placed  in commission  on first installation  unless  the apparatus  
has been  handed  over,  with prior  arrangement,  by an appointed  operator  or authorised  person  
to the system  controller.  
4.10.2 All apparatus  and control  panels  must  be suitably  labelled  and the corresponding  
operating  diagram/mimic  and operating  drawings  updated  before  apparatus  are handed  over.  
4.10.2.1 The system  controller  shall  confirm  with the appointed  operator  or authorised  
person  that all necessary  tests for commissioning  were  conducted.  
4.10.2.2 The system  controller  shall  log all relevant  information,  including  the names  and 
designations  of persons  responsible  for the tests.  
4.10.3 The system  controller  shall  be responsible  for arranging,  where  necessary,  for the 
application  of temporary  settings  of relays  on first installation  of apparatus.  PRD/ SZNS  077: 202 3 
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All rights reserved  4.10.4.1 Where  apparatus  has been  disconnected  from  a power  system  for purposes  other  
than sectionalising,  by the removal  of droppers  or jumpers  or by the opening  of links  which  
are locked  out with a unique  lock,  the key of which  is in the custody  of an appointed  operator  
or authorised  person  not directly  involved  with the operating,  the apparatus  shall  be deemed  
not to be part of the power  system.  
4.10.4.2 Any earths  necessary  on the apparatus  shall  be the responsibility  of the person  in 
charge  of the work.  
4.10.5.1 The apparatus  being  installed  shall  only become  the responsibility  of the system  
controller  once  a connection  is made  between  such apparatus  and the power  system  whereby  
it becomes  possible  for the apparatus  to be energised.  
4.10.5.2 Such  apparatus  shall  then be handed  over to the system  controller  as being  ready  
for commissioning.  
4.10.6 The appointed  operator  or authorised  person  shall  report  all required  details  of the 
apparatus  to the system  controller  and the number  and positions  of applied  earths  when  
handing  over or handing  back  such apparatus.  
4.10.7 All earths  applied  on the apparatus  to be commissioned  shall  henceforth  resort  under  
the system  controller.  
4.11 Use of Operating Diagram/Mimic  
4.11.1 The operating  diagram/mimic  at a control  centre,  power  station  control  room  or 
station  shall  be adjusted  as may be necessary  to indicate  the exact  operational  state of all 
apparatus  on the power  system  or in such station.  
4.11.2 In the event  of operating  being  performed  in any of the depicted  stations,  such 
operating  shall  not be deemed  to be completed  until the operating  diagram/mimic  concerned  
has been  adjusted  and the required  warning  notices  affixed  to indicate  the correct  operational  
state of the apparatus  affected.  
5 Access  
5.1 Access to Live Chambers , restricted areas  and Prohibited Areas   
5.1.1 Persons authorised to enter live chambers , restricted areas  or prohibited 
areas   
Only  persons  authorised  to do so, may enter  live chambers , restricted areas and prohibited  
areas.  
5.1.2 Informing the system controller when accessing a live chamber  
 An appointed  operator  shall  inform  the system  controller  before  entering  and before  leaving  
a live chamber.   PRD/ SZNS  077: 202 3 
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All rights reserved  5.1.3 Informing the system controller when accessing a prohibited area  
 An appointed  operator  or authorised  person  shall  inform  the system  controller  before 
entering  or leaving  a prohibited  area.  
5.1.4 Informing the system controller when accessing a restricted  area  
An appointed operator or authorised  person shall  inform  the system  controller  before 
entering  or leaving  a restricted area. 
5.1.5 Locking of doors and gates  
5.1.5.1 Every  door and gate giving  access  to a live chamber  or prohibited  area must  be closed  
and locked  at all times,  except  when  persons  authorised  to do so, have  entered  the live 
chamber , restricted area  or prohibited  area whereby  it is permitted  to leave  a gate or door 
unlocked  but closed  to facilitate  emergency  exit. 
5.1.5.2.1 Under  no circumstances  shall  marriage  locking  be applied  to any access  door,  gate 
or apparatus  at or in a live chamber.  
5.1.5.2.2 Marriage  locking  may be applied  at or within  certain  restricted and prohibited  areas  
where  apparatus,  which  belongs  to more  than one party,  is housed.  This shall not be 
applicable to more than two different entities or parties.  
5.1.5.2.3 Marriage  locking  may be applied  at or within  barricaded  sections  of prohibited  
areas  only where  a work  permit  has been  issued.  
5.1.5.2.4 Marriage  locking  of servitude  gates  is permissible  in mutual  agreement  with the 
land owner.  
5.2 Procedures for Access to Live Chambers of Persons other than 
Persons Authorised  
5.2.1 Access  to a live chamber  by a person  other  than an appointed  operator  shall  only be 
permitted  when  the person  is accompanied  and directly  supervised  by the appointed  
operator  so authorised  for access  and supervision.  
5.2.2 When  work  has to be performed  in a live chamber  by a person  other  than an authorized  
operator,  the person  shall  only be allowed  to work  under  the direct  supervision  of an 
authorized  operator  so authorised  for access  and supervision.  
5.2.3.1  No access  or work  may commence  unless  the live apparatus  in a live chamber  has 
been  barricaded  so as to afford  reasonable  protection  to the workers  concerned.  
5.2.3.2  In addition,  the workers  shall  sign the worker’s  declaration  as stipulated  in section  6 
of this Standard.  PRD/ SZNS  077: 202 3 
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All rights reserved  5.3 Procedures for Access to Prohibited Areas of Persons other than 
Persons Authorised  
Access  to a prohibited  area by a person  other  than an appointed  operator  or authorised  person  
shall  only be permitted  when  the person  is: 
5.3.1 Under  supervision  of an appointed  operator  or authorised  person;  
5.3.2 working  on ground/floor  level  under  a work  permit  with the worker’s  declaration  duly 
signed  and the workplace  suitably  barricaded;  
5.3.3 protected  by barricading,  erected  in such a way to ensure  that inadvertent  human  
contact  with live apparatus  adjacent  to the barricaded  area is not possible  from  within  the 
barriers  and within  safe working  clearance;  
5.3.4 in a section  of a prohibited  area,  segregated  from  the remainder  of the prohibited  area 
in which  access  or work  must  be carried  out, in which  case the section  of the prohibited  area 
no longer  constitutes  a prohibited  area and no supervision  by an appointed  operator  is 
required.  
5.4 Duties to Perform when Gaining Access to Prohibited Areas or 
Live Chambers  
5.4.1 An appointed  operator  gaining  access  to a prohibited  area,  live chamber,  station  or 
building  and an authorised  person  gaining  access  to a prohibited  area,  station  or building  
must  observe,  log and report  abnormalities  on the condition  of all warning  notices,  
nameplates,  locks  and fencing,  earthing,  oil leakages,  vegetation,  obstacles,  trenches,  covers,  
air conditio ning (if installed)  and the general  condition  of the visited  area.  
5.4.2 An appointed  operator  or authorised  person  must  deny  access  to any unidentified  
person (s). 
5.5 Staying Overnight in Live Chambers or Prohibited Areas  
5.5.1 Staying  overnight  in a live chamber  shall  not be permitted  under  any circumstance.  
5.5.2 Staying  overnight  within  any prohibited  area or building  is normally  not permitted  to 
any person,  but an appointed  operator  or authorised  person  with or without  accompanying  
persons  may under  certain circumstances  stay overnight,  if - 
5.5.2.1  the logbook  is properly  filled  in depicting  clearly  the circumstances  that requires  this 
exception;  
5.5.2.2  the system  controller  has been  informed;  
5.5.2.3  the person  in charge  has been  informed.  
5.5.3 The appointed  operator  or authorised  person  and accompanying  persons,  if any, shall  
observe  the following  restrictions  at all times:  PRD/ SZNS  077: 202 3 
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All rights reserved  5.5.3.1  No open  fire is permitted  in the building;  
5.5.3.2  open  fires for heating  or preparation  of food shall  only be permitted  in an area outside  
the building  demarcated  for that purpose  by the person  in charge;  
5.5.3.3  no alcoholic  beverage , no consumption of food  is permitted  in any prohibited  area,  
live chamber  or building ; 
5.5.3.4 All relevant PPE shall be worn at all times.  
5.6 Electric Fences  
5.6.1 Only  a fence  energiser  that delivers  impulses  of electricity  to an electric  fence,  which  
are equal  to or within  the following  values,  may be installed:  
5.6.1.1  Peak  value  of voltage:  10 kilovolt s (10 kV);  
5.6.1.2  maximum  duration  of impulse:  50 milliseconds  (50 ms); 
5.6.1.3  minimum  interval  between  impulses:  0,75 second;  
5.6.1.4  maximum  quantity  of electricity  per impulse:  2,5 millicoulomb  (2,5 mC) (electrical  
charge);  
5.6.1.5  maximum  electricity  discharge  per impulse  measured  at a resistance  of 500 ohms:  8 
Joule  (8 J). 
5.6.2 A fence  energiser : 
5.6.2.1  must  be constructed  so as to exclude  dust and water;  
5.6.2.2  may not be installed  in a dusty  location  or a location  where  there  is a fire hazard.  
5.6.3 A fence  energiser,  which  receives  its electrical  charge  from  a power   system , may 
not be installed : 
5.6.3.1  in locations  where  the energiser  is likely  to sustain  mechanical  damage  or be 
tampered  with;  
5.6.3.2  on any pole of a power  or communication  line except  a pole that carries  the conductor  
of the energiser;  and 
5.6.3.3  unless  the output  circuit  is isolated  from  the supply  by means  of a double -wounded  
isolating  transformer.  
5.6.4 The earth  of a fence  energiser  shall  be free and at least two metres  away  from  the earth  
of any other  apparatus.  
5.6.5.1  Barbed  wire may not be electrified  but only smooth  wire or such article  as will enable  
a person  touching  it to let go immediately.  
5.6.5.2  Smooth  wire attached  to a barbed  wire fence  may be electrified.  PRD/ SZNS  077: 202 3 
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All rights reserved  5.6.6 In the case of a fence  energiser  receiving  electricity  from  a battery  charged  by means  
of charging  apparatus,  which  receives  its electrical  charge  from  a power  system,  the 
charging  apparatus  shall  be of double -wounded  isolation  construction.  
5.6.7 Where  an electric  fence  is installed :  
5.6.7.1  the electrified  wires  or articles  shall,  as far as is practicable,  be mounted  in such 
positions  that persons  cannot  inadvertently  come  into contact  therewith;  and  
5.6.7.2  notices  shall  be displayed  conspicuously,  warning  people  that the area is protected  
by an electric  fence.  
5.7 Procedures for Access of Persons to Restricted Areas other than 
Persons Authorised  
 Access  to restricted  areas  shall  be allowed  only to a person  who has obtained  permission  
through  an authorised  method.  
5.8 Access to and Work in Fire Protected Areas  
5.8.1 Automatic Control  
Unless alternative approved  procedures apply because of special circumstances then before 
access to, or work or other activities are carried out in, any enclosure protected by automatic 
fire extinguishi ng equipment:  
i. The automatic control shall be rendered inoperative, and the equipment left on hand 
control and where the facility exists, locked . A Caution Notice shall  be attached;  
ii. Precautions taken to render the automatic control inoperative and the condi tions under 
which it may be restored shall  be noted on any safety document  or written instruction 
issued for access, work, or other activity in the protected enclosure; and,  
iii. The automatic control shall  be restored immediately after the persons engaged on the 
work, or other activity, have withdrawn from the protected enclosure.  
5.8.2 Portable Fire Extinguishers  
Only approved  portable fire extinguishers shall  be available and used in the vicinity of live 
appara tus and conductors. In the handling of fire extinguishers, the appropriate safety 
distances shall  be maintained. After the discharge of portable fire extinguishers in an 
enclosed space, personnel shall  leave the space until precautions have been taken.  
5.8.3 General 
After any explosion to fire, or after the discharge of fire extinguishers in an enclosed space, 
either the space shall  be adequately ventilated before the entry of personnel, or approved  
breathing apparatus and, where necessary, approved  safety harnesses shall  be worn by 
persons specially trained in their use. Such breathing apparatus and safety harnesses shall be 
worn in any case of doubt.  PRD/ SZNS  077: 202 3 
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All rights reserved  6 Keys  
6.1 Issuing and Control of Master Keys  
The responsible  official  shall  issue  and control  all master  station  keys.  
6.2 Issuing and Use of Station Keys   
6.2.1 Every door giving access to a live chamber, restricted or prohibited area shall normally 
be closed and locked. Never leave keys unattended to.  
6.2.2 Station  keys shall  only be issued  to specially  traine d persons  on the written  authority  
of the person  authorised  by the responsible  official  to issue  station  keys.  
6.2.3 Station  keys shall  only be issued  to a person  other  than a specially  trained  person  with 
the prior  written  approval  of the responsible  official.  
6.2.4.1 The issuing  of a station  key must  be recorded  in a register , stating  to whom  the key 
is being  issued  and the time and date of issue.  
6.2.4.2 In all cases  the signature  of the person  receiving  the key and that of the person  issuing  
the key must  be entered  against  the record.  
6.2.4.3 Similarly,  when  a station  key is returned,  its receipt  must  be recorded  in the logbook.  
6.2.5.1 Any person  to whom  a station  key has been  issued,  is held solely  responsible  for such 
key while  in his or her possession.  
6.2.5.2 The person  may not let any such key pass out of his or her possession.  
6.2.6 The special  operating  procedures  shall  include  without  limitation,  procedures  
pertaining  to: 
i. the requirements  of a key safe system;  
ii. the marking  of keys and locks;  
iii. the issuing  and use of keys at stations  for live chambers  and prohibited  areas;  
iv. the surrender  or loss of keys;  and 
v. the use of keys when  changing  over busbars.  
6.2.7 Loss of keys shall be reported immediately to the Official in -charge.  
6.3 Issuing and Use of Personal Safety Padlocks  
6.3.1 All employees shall have a personal safety padlock engraved with a unique 
identification number.  
6.3.2 The issuing of personal safety padlocks must be recorded in a register, stating to whom 
the padlock is being issued  and the time and date of issue.  
6.3.3 A” one man – one padlock” rule must be obeyed by all people working on the isolated 
equipment and under no circumstances may another person insert or remove another PRD/ SZNS  077: 202 3 
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All rights reserved  person’s padlock or even share padlocks. Each lock s hould only have one key (no master 
keys are allowed).  
6.3.4 A "Lockout Tag" which has details of the Permit Issuer, Permit holder and team 
members shall be attached on the calliper.  
6.3.5 In the event of a person leaving the premises without removing his p adlock the 
following is to be applied: - 
6.3.5.1 The Head of section shall ensure that the padlock owner is located and brought to 
site to remove his /her padlock  
6.3.5.2 Where the owner cannot come to site to remove his padlock. The Head of Section 
including the Official in -charge  shall authorise the cutting of padlock after having taken all 
possible means to ensure that no other person may be injured by removing the padlo ck. 
6.3.5.3 Amongst others, this will include consulting the Permit Issuer and Holder, as wel l as 
physically checking the worksite and unit to be de -isolated.  
6.3.5.4 An incident shall be raised and investigated to determine the root cause of the team  
memb er not removing his /her padlock, closure of such incidents shall be approved by the 
official in charge.  
7 Work Permits  
7.1 Circumstances When A Work Permit Is Required  
 A work  permit  is required  for all work  on apparatus  or in live chambers , restricted  areas  and 
prohibited  areas  at any place  in a power  station , power substation  or on a transmission  
system,  a distribution  system  or a low voltage  system,  except  as provided  for in paragraph  
7.3.14  of this Standard.  
7.2 Forms in Duplicate  
7.2.1 The appointed  operator  shall  make  out work  permit  forms  in duplicate.  
7.2.2 The authorised  person,  responsible  person  or contractor  shall  retain  the original.  
7.2.3 A copy  shall  be left in the work  permit  book,  which  shall  be retained  by the appointed  
operator  until it is cancelled  or closed . 
7.3 Use of Work Permit Form  
7.3.1 Application  and permit  
7.3.1.1  When  work  under  the permit  procedure  is to be carried  out, the responsible  employee  
shall  provide  the appointed  operator  with all the details  to be filled  in on the application,  
confirm  the details  and sign the application  stating  - 
7.3.1.1.1  the apparatus  required  to be made  safe;  
7.3.1.1.2  the nature  of the work  to be carried  out; PRD/ SZNS  077: 202 3 
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All rights reserved  7.3.1.1.3  the points  of isolation;  
7.3.1.1.4  the number  and position  of earthing  gear necessary;  and 
7.3.1.1.5  the time and date on which  the work  has to commence.  
7.3.1.2  After  signing  the application,  the appointed  operator  shall  make  arrangements  with 
the system  controller  to have  the apparatus  isolated,  earthed  and barricaded.  
7.3.2 Work permit   
7.3.2.1 The system controller must  issue  the work  permit  to the responsible  person,  after he 
or she has physically  inspected  and agreed  that the required  apparatus  is isolated,  earthed,  
barricaded  (if required)  and handed  out according  to the application.  
7.3.2.2  The responsible  person  must  ensure  that all persons  working  under  the work  permit  
are informed  about  the safety  of the apparatus  to be worked  on. 
7.3.2.3  The worker’s  declaration  has to be filled  in and signed  by all workers  engaged  in the 
work  and the responsible  person  must keep  the original  declaration  in safe custody.  
7.3.2.4  The appointed  operator  and the responsible  person  must  then sign and record  the 
date and time of the work  permit.  
7.3.2.5  The original  work  permit  form  must  be detached  from  the permit  book  and handed  
to the responsible  person  together  with any keys necessary  to give access  to the apparatus  
concerned.  
7.3.2.6  The work  permit  form  reference  number  must  be reported  to the system  controller,  
upon  which  the responsible  person  is deemed  to have  taken  over the apparatus  to be worked  
on. 
7.3.3 Worker’s declaration  
7.3.3.1  The responsible  person  must  explain  the nature  of the work  covered  by the work  
permit  to all workers  engaged  in the work  and must  obtain  all their names  and signatures  on 
the worker’s  declaration  form.  
7.3.3.2  The responsible  person  must  keep  the worker’s  declaration  updated  for the duration  
of the work  permit.  
7.3.3.3  Upon  completion  of the work,  all workers  engaged  in the work  must  sign off the 
declaration  understanding  that the work  has been  completed  and that nobody  is permitted  
any longer  in the workplace.  
7.3.4 Clearance  
7.3.4.1  On completion  of any work  for which  a work  permit  was issued  the responsible  
person  must  ensure  that all workers  engaged  in the work  are withdrawn  from  the apparatus  PRD/ SZNS  077: 202 3 
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All rights reserved  or the live chamber  or prohibited  area concerned  and must  lock all doors  or gates  giving  
access  to the apparatus,  live chamber  or prohibited  area.  
7.3.4.2  The responsible  person  must  then fill in and sign the clearance  section  of the work  
permit  form  in his or her possession  and must  return  any keys issued  for the work,  together  
with the original  form  of the work  permit  form  to the system controller . 
7.3.4.3  The responsible person  must :  
7.3.4.3.1inspect  the completed  work  and the removal  of all surplus  materials  and tools;  and 
7.3.4.3.2  check  all electrical  clearances;  and 
7.3.4.3.3  ensure  that all contractors  and workers  are withdrawn,  before  the clearance  is 
countersigned.  
7.3.4.4  At power  stations,  when  work  is completed  at more  than one place  in a circuit,  each 
work  permit  must  be cancelled  by the issue  of a clearance  on the completion  of each separate  
item of the work  but no earths  may be removed  from  any section  of the apparatus  until 
clearances  are received  for all work  permits  which  were  issued  for work  on the circuit.  
7.3.4.5  Before  the hand  back  of the feeder  or apparatus  for commissioning,  the responsible 
person  must  ensure  that all warning  notices  have  been  removed.  
7.3.4.6  Should  the appointed  operator  to whom  the feeder  or apparatus  was handed  out for 
work  not be available  for any reason,  the system  controller  must  liaise  with another  
appointed  operator  as to the present  operational  state of the feeder  or apparatus  and then 
decide  which  other  available  appointed  operator  must  be instructed  to do the hand  back  of 
the feeder  or apparatus.  
7.3.4.7  In either  case the system  controller  must  take all reasonable  steps  to ensure  that no 
deviation  from  this Standard  will arise  as a result  of such transfer  of responsibility.  
7.3.4.7.1 If a responsible person for a work permit has to leave the work site, the permit shall 
be cancelled or closed , and another responsible person shall be issued with a new work 
permit by the system controller.  
7.3.5 Return to service  
 The responsible person  must  complete  the clearance  section  by signing  it and must  notify  
the system  controller  that the clearance  of the work  permit  of the feeder  or apparatus  and 
the original  worker’s  declaration  was received  and that the feeder  or apparatus  is ready  to 
be handed  back.  
7.3.6 Non-availability of original form  
7.3.6.1  If the original  of the work  permit  form  is not available  when  the clearance  of the 
work  permit  is required,  the responsible person  must  confirm  that all workers  have  been  PRD/ SZNS  077: 202 3 
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All rights reserved  withdrawn  from  the workplace  and the appropriate  section  of the workers  register  has been  
signed.  
7.3.6.2  The responsible person  must  then countersign  the copy  of the work  permit,  which  
signature  authorises  the system controller  to clear  the work  permit  in question.  
7.3.7 Original forms  
7.3.8.1  Each  completed  work  permit  book  containing  the copies  of work  permit  forms  shall  
be returned  to the official  in charge  when  a new book  is put in use. 
7.3.8.2  Such  completed  book  may be destroyed  on instructions  from  the official  in charge  
after the expiry  of the period  determined  by the licensee,  if no query  has arisen  during  such 
period  regarding  any entry  contained  in it. 
7.3.8 Duration of permit  
A permit  shall  remain  in force  until it is cancelled  or closed  by the issuing  of a clearance , it 
shall not last for a period exceeding 24 hours.  
7.3.9 Work may only be done under one permit at a time  
No person  may work  under  more  than one work  permit  at a time.  
7.3.10  Issuing of more than one permit  
 A responsible  person  may be issued  with more  than one work  permit  at a time:  Provided  
that the responsible  person  is not directly  involved  with the work  and can exercise  an 
adequate  level  of supervision  at each workplace.  
7.3.11  Work permits are required for each circuit  
 When  it is necessary  to perform  work  on apparatus  at a power  station  in more  than one 
chamber  on the same  circuit,  a separate  work  permit  shall  be issued  for the work  in each 
separate  circuit.  
7.3.12  Work on apparatus involving licensees, customers and contractors  
7.3.12.1. Where  it is necessary  to isolate  and earth  the supply  apparatus  of a licensee,  
customer  or contractor  to enable  work  on such apparatus,  a work  permit  must  be used.  
7.3.12.1.2 A representative  of the licensee,  customer  or contractor  must  sign the work  permit  
as the responsible  person.  
7.3.12.2 In the event  of apparatus  being  isolated  by a licensee  or customer  without  an 
established  control  centre  and there  could  be a possible  back  feed into the supply  system,  
the system  controller  and the responsible person  are responsible  for rendering  such isolating  
equipment  inoperative,  by locking  out such apparatus  with a unique  lock for the period  that 
the work  is in progress.  PRD/ SZNS  077: 202 3 
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All rights reserved  7.3.12.3 If the licensee  or customer  has an established  control  centre,  the work  permit  
procedure  does not apply  and all required  operating  must  be effected  between  the control  
centre  and the related  control  centre  concerned,  but all apparatus  on which  work  has to be 
performed  must  be locked  with a unique  lock.  
7.3.13  Cases  where  a work  permit  is not required : 
7.3.13.1 No work  permit  is required  when  only an appointed  operator  carries  out work  on a 
feeder  or apparatus  together  with the workers  working  under  the direct  supervision  of the 
appointed  operator.  
7.3.13.2 No work  permit  is required  when  an authorised  person  is carrying  out specific  pre-
defined  work  in a prohibited  area.  
7.3.13.3 No work  permit  is required  where  testing  of equipment  is carried  out in accordance  
with paragraph  8.3.15 of this Standard.  
7.3.1 3.4 In a case were a work permit is not needed, a person will require permission from 
a system controller in the form of a supporting document e.g. sanction for test, job cards , 
service or work orders,  etc. 
8 Authorized Operation  
8.1 Persons Authorised to Perform Switching, Linking, Safety Testing 
and Earthing Operations  
8.1.1 Only  appointed  operators  shall  carry  out switching,  linking,  safety  testing  or earthing  
operations  to the extent  of their authorisation  under  instruction  of the system  controller.  
8.1.2 Persons  being  trained  for operating  authority  shall  operate  under  the direct  supervision  
of an appointed  operator,  if the system  controller  has been  duly informed  of such 
arrangement.  
8.1.3 Authorised  persons  in stations  may render  auxiliary  services  on pre-defined  auxiliary  
apparatus,  excluding  the switching  of auxiliary  apparatus  on auxiliary  circuits  by hand  or 
remote  control,  and the hand  out and hand  back  procedures  must  be confirmed  with the 
system  controller  and must  be logged.  
8.1.4 If any work  is to be performed  on auxiliary  apparatus,  the hand  out and hand  back  
procedures  must  be followed  and logged.  
8.1.5 Changing  of relay  settings  on apparatus  must  be authorized  by the system bcontroller  
and is subject  to prior  hand  out and hand  back  procedures.  
8.2 Procedure for Work in Live Chambers  
 No person  may enter  or be allowed  to perform  any activity  or work  in a live chamber,  unless  
the live apparatus  in the chamber  has been  effectively  barricaded  or isolated  and earthed.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3 Making Feeders and Apparatus Safe to Work On  
8.3.1 All operating to be carried out under instruction from  the system 
controller  
8.3.1.1  All operating  on apparatus  on a power  system  shall  be carried  out under  instruction  
of the system  controller.  
8.3.1.2.1  Before  any instructions  are issued,  the authorised  person  shall  discuss  in detail  with 
the system  controller,  all work  to be carried  out, including  potentially  dangerous  conditions  
which  may exist.  
8.3.1.2.2  All parties  shall  refer to corresponding  operating  diagrams  and shall  agree  to the 
relevant  operating.  
8.3.2 Emergency switching  
8.3.2.1  In the case of an emergency,  any person  may open  any switch  or circuit  breaker,  
but only in so far as it is necessary  to prevent  loss of life or injury  to persons  or damage  
to property.  
8.3.2.2  Full details  of every  such event  shall  be reported  to the system  controller  as soon  
as possible  after the event.  
8.3.3 Isolating from supply under direct instruction from system controller  
8.3.3.1.1  Where  it is necessary  to operate  at two or more  points,  which  are not at the same  
location,  the operating  may be performed  by a corresponding  number  of appointed  operators,  
but all the operating  detailed  in this Standard  must  be performed  by one appointed  operator  
only for each point.  
8.3.3.1.2  The system  controller  shall  inform  the authorised  person  that the breakers  and 
isolators  at each point  controlling  the feeder  have  been  opened.  
8.3.3.2  Where  continuous  shift working  is in operation  at a station,  the appointed  operator  
or authorised  person  may hand  over the shift to another  appointed  operator  or authorised  
person  only if all operating  instructions  issued  by the system  controller  to such appointed  
operator  or authorised  person  have  been  fully  carried  out. 
8.3.3.3.1  Where  it is impracticable  for one or more  appointed  operators  to obtain  direct  
communication  with the system  controller,  written  instructions  may be relayed  through  a 
third  person  to another  appointed  operator.  
8.3.3.3.2  The third  person  must  write  down  the operating  instructions  as issued  by the system  
controller,  and re-read them  word  for word  to the appointed  operator.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.3.4  Where  a breaker  of links  can be controlled  from  a remote  point  over which  the 
appointed  operator  has no control,  such facilities  shall  be switched  off or otherwise  made  
inoperative  by the appointed  operator  before  isolation  is commenced.  
8.3.3.5.1  No earthing  operation  shall be authorised  by the system  controller  until isolation  
has been  completed  at all points  of supply.  
8.3.3.5.2  The system  controller  shall  inform  the appointed  operator  that the breakers  and 
links  at each point  of supply  controlling  the feeder  have  been  opened.  
8.3.3.6  Effective  isolation  may only be achieved  by:  
8.3.3.6.1  the opening  of an isolator  or suitable  switch;  
8.3.3.6.2  the racking  out of a circuit  breaker , in which  case the opening  only of a circuit  
breaker  or sectionaliser  (in tank)  is not isolation;  
8.3.3.6.3  the removal  of drop out fuses  or opening  of links  on all phases;  
8.3.3.6.4  the physical  removal  of suitable  connections  on all phases.  
8.3.3.7  Except  in the case of an emergency,  operating  shall  not be carried  out until all persons  
not directly  performing  the operating  have  withdrawn  to a reasonable  distance  in case of a 
fault while  switching  is taking  place.  Arc flash clearances standards as per voltage ratings . 
8.3.4 Links and drop out fuses  
8.3.4.1  Links  which  are accessible  to persons  not authorised  to possess  station  keys shall  be 
kept locked  at all times  except  when  being  operated.  
8.3.4.2  Links  shall  only be operated  with all load removed  from  the circuit  they control  and, 
if possible,  with the circuit  de-energised.  
8.3.4.3.1  Drop  out fuses  shall  be operated  with due regard  to the likely  load current  and the 
power  system  conditions.  
8.3.4.3.2  If the prospective  load current  is high,  the load shall  be removed  or the line de-
energised  before  operating  the fuses.  
8.3.4.4.1  Drop  out fuses  shall  not be reclosed  after a fault unless  the line has been  de-
energised  or the fault has been  positively  identified  and corrected.  
8.3.4.4.2  Drop  out fuses  of single  transformers  may be reclosed  with all load from  the low 
voltage  side removed.  
8.3.4.5  Links  and drop out fuses  shall  only be operated  with an approved  operating  stick  
from  outside  the safe working  clearance  unless  the circuit  has been  isolated,  safety  tested,  
earthed  and handed  out to the appointed  operator.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.5 Bypassing of interlocks  
8.3.5.1  Except  as expressly  permitted  in this Standard,  interlocks  shall  not be bypassed  or 
defeated  without  the express  authority  of the person  in charge.  
8.3.5.2  Each  incidence  of bypassing  an interlock  shall  be specifically  recorded  in the 
logbook  kept by the system  controller,  and the logbook  in the station.  
8.3.6 Safety -testing of feeders and apparatus after isolating from supply  
8.3.6.1  Immediately  before  applying  an earth  at a point,  the appointed  operator  shall  use a 
testing  device  provided  for the purpose  to ensure  that the feeder  or apparatus  is dead  at each 
such point  where  an earth  is to be applied.  
8.3.6.2  The appointed  operator  must  ensure  that the testing  device  is in proper  working  order  
and suitably  rated  for the voltage  levels  before  it is used.  
8.3.6.3  In the case of certain  apparatus  which  cannot  be safety  tested  before  earthing,  the 
earth  shall  be applied  in a manner  approved  by the licensee  to prevent  danger.  
8.3.6.4.1  Where  cables  have  been  isolated  and earthed  and work  on either  of the end 
terminals  is necessary,  without  these  end terminals  having  been  tested,  the terminal  boxes  
will be opened  and the terminals  tested  with an approved  testing  device.  
8.3.6.4.2  Covered  terminals  shall  be tested  before  any attempt  is made  to intrude  on the 
covering.  
8.3.6.5  Where  a cable  has to be cut, the cable  shall  be spiked  using  an approved  spiking  
device  before  the cable  is cut. 
8.3.6.6  After  a feeder  or apparatus  has been  earthed,  the appointed  operator  shall  be satisfied  
that the feeder  or apparatus  is discharged.  
8.3.7 Warning notices and earth labels  
8.3.7.1  Exhibition  of warning  notices  in stations  
8.3.7.1.1  Before  isolating  a feeder  or apparatus,  a warning  notice  shall  be affixed  on each 
control  panel  corresponding  with such apparatus.  
8.3.7.1.2  No isolation  of a feeder  or apparatus  shall  be deemed  to be complete  until a suitable  
warning  notice  has been  affixed  at each point  from  which  such feeder  or apparatus  can 
inadvertently  be made  alive.  
8.3.7.1.3  The warning  notice  may not be detached  until all earths  have  been  removed  and 
the feeder  or apparatus  is ready  to be made  alive.  
8.3.7.1.4  A warning  notice  on the control  panel  shall  be the last to be removed.  
8.3.7.2  Use of control  panel  labels/tags  at power  stations : PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.7.2.1.1  When  any apparatus  at a power  station  is earthed  in preparation  for work  on it, 
or any feeder  is earthed  for work  external  to the station,  as soon  as the earthing  operation  
has been  reported  to the system  controller,  a control  panel  label/tag  shall  be completed  by 
the appointed  operator  stating  the number  and position  of the earthing  gear and the permit  
number,  if one has been  issued.  
8.3.7.2.1.2  The original  control  panel  label/tag  shall  be detached  and affixed  to the control  
panel  of the apparatus  so earthed.  
8.3.7.2.2  The appointed  operator  shall  on the instruction  of the system  controller  remove  the 
control  panel  label/tag  after the apparatus  has been  handed  back  and when  the operation  or 
the removal  of the earthing  gear to which  it relates,  has been  completed.  
8.3.7.3  Use of warning  notices  at stations : 
8.3.7.3.1  After  apparatus  has been  isolated  and tested  to be dead,  earths  must  be applied  in 
preparation  to work  on. 
8.3.7.3.2.1  Warning  notices  must  be affixed  to the related  control  panel  by the appointed  
operator.  
8.3.7.3.2.2  The appointed  operator  must  remove  all the warning  notices  after the related  
earths  have  been  removed  as instructed  by the system  controller.  
8.3.8 Earthing  
8.3.8.1  All earthing  must  be so designed  to be capable  of withstanding  the full fault current  
flowing  through  it for a specified  period  of time in such a manner  as will ensure  an immediate  
safe discharge  of electrical  energy  at all times.  
8.3.8.2  Only  an approved  means  of earthing  shall  be used.  
8.3.8.3  Minimum earthing requirements  
8.3.8.3.1  Stations  
8.3.8.3.1.1  Apparatus  
 When  apparatus  other  than a line or a busbar  has been  isolated  from  all points  of supply  and 
tested  in accordance  with this Standard,  it shall  be earthed  at least at all such isolated  points  
of supply.  
8.3.8.3.1.2  Busbar  
8.3.8.3.1.2.1  When  a busbar  has been  isolated  from  all points  of supply  and tested  to be dead,  
it must  be earthed  at least at one such isolated  point  of supply.  
8.3.8.3.1.2.2  For work  on busbars,  prior  arrangements  must  be made  with the system  
controller  for the application  of an additional  earth.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.8.3.1.2.3  An additional  earth  may be applied  and moved  along  the busbar  as required  
during  the course  of work  without  further  reference  to the system  controller.  
8.3.8.3.1.2.4  Should  any other  earth  be required  on a busbar,  working  earths  may be applied.  
8.3.8.3.1.2.5  For earthing  of busbars  in switching  stations,  prior  arrangements  must  be made  
with the system  controller  when  sequence  keys are used for the application  of a busbar  earth.  
8.3.8.3.1.3  Transformers  
8.3.8.3.1.3.1  When  a transformer  has been  isolated  from  all points  of supply  and tested  to be 
dead,  each winding  of the transformer  must  be earthed  at its isolated  points  of supply,  except  
when  a transformer  winding  cannot  be earthed  at its point  of supply  or at any other  part of 
the circuit  between  the winding  and its point  of supply.  
8.3.8.3.1.3.2  It is permitted  to work  on the circuit  if it has been  isolated  and the other  
windings  of the transformer  have  been  earthed  at their isolated  points  of supply.  
8.3.8.3.1.3.3  An auxiliary  or tertiary  low voltage  supply  from  a transformer  must  be isolated  
at all points  of supply  and the breakers  or isolators  locked  in the open  position  with an 
interlocking  key, safety  lock,  unique  lock or operating  lock,  where  possible.  
8.3.8.3.1.3.4  If it is not possible  to lock out breakers  or isolators,  a warning  notice  must  be 
affixed  to the relevant  breaker  or isolator  indicating  that work  is in progress  on the circuit.  
8.3.8.3.1.4  Metal  clad switch  gear 
8.3.8.3.1.4.1  Totally  enclosed  metal  clad switch  gear shall  be earthed  only by means  of the 
approved  earthing  gear provided  as part of the switch  gear.   
8.3.8.3.1.4.2  If the earthing  gear is not available  then any alternative  equipment  must  be 
approved  before  use.  
8.3.8.3.1.4.3  The insertion  of hands  or any other  tools  into the contact  spouts  for this purpose  
is forbidden.   
8.3.8.3.2  Lines   
8.3.8.3.2.1  When  a line or section  of a line has been  isolated  from  all points  of supply  and 
tested  to be dead,  it shall  be earthed  at all such points  of supply.   
8.3.8.3.2.2  Before  any work  may commence,  the line must  again  be tested  to prove  that it is 
dead  where  after the appointed  operator  shall  apply  sufficient  working  earths  on the line on 
all sides  of the point  of work,  which  are clearly  visible  from  the point  of work.   
8.3.8.3.2.3  Where  sections  of the overhead  guard  conductor  of a line are insulated  from  the 
tower,  and the possibility  of induction  exists,  the overhead  guard  conductor  shall  be earthed.
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All rights reserved  8.3.8.3.2.4  When  a static  var compensator  (SVC)  or capacitor  bank  has been  isolated  from  
all points  of supply  and tested,  it shall  be earthed  at all points  of supply.   
8.3.8.3.2.5  Adequate  earths  shall  be applied  in accordance  with equipment  specific  earthing  
procedure  to ensure  that all possible  trapped  charges  will be discharged  for the duration  of 
the work.  
8.3.8.3.3  Working  earths  
8.3.8.3.3.1  If work  must  be done  on exposed  conductors  and it is not obvious  from  the 
workplace  that the apparatus  has an earth  applied,  an additional  earth  which  is clearly  
visible  from  the workplace  shall  be affixed  to the apparatus.  
8.3.8.3.3.2  If the conductors  are to be cut or otherwise  separated,  additional  working  earths  
shall  be applied  before  separating  the conductors  so that one working  earth  is on each side 
of the break.  
8.3.8.3.3.3  The person  in charge  of work  may also at his or her discretion  arrange  for an 
additional  earth  to be affixed  to the apparatus.  
8.3.8.3.3.4  Working  earths  shall  be applied  and bonded  on all sides  of the workplace.  
8.3.8.3.4  Portable  earthing  gear 
8.3.8.3.4.1  Testing  to be dead  on all three  phases,  where  applicable,  as an operating  
instruction,  must  be performed  before  any earthing  gear may be applied.  
8.3.8.3.4.2  When  using  portable  earthing  gear,  it must  first be connected  to earthed  
metal  work,  or a suitable  earth  spike  driven  to a minimum  of 750mm  into the ground  where  
no earthed  metal  work  is accessible.  
8.3.8.3.4.3  The other  tails of the portable  earths  shall  then be connected  to the feeder  or 
apparatus  to be earthed,  making  use of an approved  operating  stick  suitably  rated  for the 
operating  voltage.  
8.3.8.3.4.4  All sides  of the apparatus  or feeder  must  be bonded  and earthed.  
8.3.8.3.4.5  The authorised  person  shall  secure  the portable  earths  to the phases  by means  of 
an approved  operating  stick  suitably  rated  for the operating  voltage  and care must  be taken  
to ensure  that good  contact  is made.  
8.3.8.3.4.6  Portable  earths  shall  not be applied  in any compartment,  cell or switch  bay in 
which  there  is any exposed  live metal  parts  at medium  or high voltage  and where  there  is a 
chance  of inadvertently  bringing  the earth  connection  within  the safe working  clearance  of 
the live metal  parts.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.8.3.4.7  On removal  of the earth,  the procedure  must  be reversed  by first removing  the 
tails from  the feeder  or apparatus  and lastly  to disconnect  the tail connected  to the earthed  
metal  work,  earth  mat or earth  spike.  
8.3.8.3.5  Earthing links/switches  
8.3.8.3.5.1  When  apparatus  equipped  with earthing  links/switches  are required  to be earthed  
at more  than one place,  the earthing  links/switches  shall  always  be closed  first and thereafter  
any necessary  earthing  gear may be affixed  to the apparatus.  
8.3.8.3. 5.2 In removing  earths  for preparation  to make  the apparatus  alive,  all working  earths  
must  be removed  first, followed  by removing  additional  earths,  if applicable,  and then the 
earthing  links/switches  must  be opened  last. 
8.3.9 Work on lines  
8.3.9.1  Handing over a line or section of a line for work  
8.3.9.1.1  Before  handing  out a line or section  of a line for work,  the system  controller  shall  
ensure  that the auto-reclose  features  on all breakers  controlling  the supply  to the line have  
been  switched  off or rendered  inoperative  and that warning  notices  are displayed  on all the 
breaker  control  points.  
8.3.9.1.2  The line shall  then be handed  over to the appointed  operator  by the system  
controller,  who shall  authorise  the application  of working  earths,  where  required,  and on 
completion  of the work,  the removal  of all such working  earths.  
8.3.9.1.3  Immediately  after a line or section  of a line has been  handed  over to the appointed  
operator,  the system  controller  shall  affix  the name  of such appointed  operator  to the line or 
section  of the line on the operating  diagram/mimic.  
8.3.9.2  Isolated power lines  
8.3.9.2.1  Full understanding  
 Before  the commencement  of any work  on a power  line, the responsible  person  in charge  of 
that work  shall  ensure  that every  person  who is to work  on any part of the power  line is fully  
informed  of and understands  on which  components  the work  is to be carried  out and that the 
person  signs  a worker’s  declaration  form  that he or she so understands.  
8.3.9.2.2  Towers , poles  and high structures  
8.3.9.2.2.1  Any person  working  on any tower , pole or high structure  shall  make  proper  use 
of his or her safety  belt. 
8.3.9.2.2.2  No person  shall  work  from  a ladder  at a high structure  unless  there  is another  
person  at the site to assist  him or her, where  necessary.  
8.3.9.2.2.3  Before  any pole is climbed,  either  directly  or from  a ladder,  it shall  be examined  
for any deterioration.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.9.2.2.4  If the condition  of a pole is doubtful,  it shall  not be climbed  without  the express  
permission  of the authorised  person  in charge.  
8.3.9.2.3  Working  earths  
8.3.9.2.3.1  No work  shall  be started  on any power  line until working  earths  in addition  to 
the registered  earths  have  been  applied  under  the immediate  personal  supervision  of the 
authorised  person  in charge  of the work  at each side of the workplace  within  his or her sight.  
8.3.9.2.3.2  The working  earths  shall  be issued  by the authorised  person,  who shall  be 
responsible  for ensuring  that they are all returned  to him or her before  the hand  back  to the 
system  controller  is given.  
8.3.9.2.4  Disconnecting  part of a power  line 
8.3.9.2.4.1  Before  disconnecting  part of a power  line from  the portion  being  worked  on, 
additional  working  earths  shall  be applied  as specified  in paragraph  8.3.9.2.3  of this 
Standard  to ensure  that each of the sections  of the power  line so disconnected  complies  with 
the earthing  requirements.  
8.3.9.2.4.2  The working  earths  shall  be left connected  to the power  line for as long as anyone  
is working  on either  of the two disconnected  sections.  
8.3.9.2.5  Break  in work  
 If the authorised  person  in charge  of the work  leaves  the workplace  so that he or she cannot  
see the point  of work  and later returns  to restart  work,  he or she shall  personally  verify  that 
all working  earths  are still in place  before  work  recommences.  
8.3.9.2.6  Adverse  weather  conditions  
 In the event  of the near approach  of a lightning  storm  or if the wind  speed  rises to a level  
where  the authorised  person  in charge  of the work  considers  it to be dangerous,  all work  
shall  be suspended  and all workers  withdrawn  to ground/floor  level  until conditions  become  
safe again.  
8.3.9.3  Special conditions for power lines  
8.3.9.3.1  If necessary  because  of distance  and time constraints  and if the authorised  person  
in charge  of the work  is satisfied  that there  is no opportunity  for misunderstanding,  the 
following  procedure  may be used for power  line work:  
8.3.9.3.1.1  The authorised  person  in charge  of the shutdown  shall  take the responsible  person  
to the section  of the line where  work  is to be carried  out and ensure  that the responsible  
person  is fully  aware  of the work  to be performed;  
8.3.9.3.1.2  the authorised  person  shall  give the responsible  person  a work  permit  which  is 
complete  in all details  except  the time,  which  has been  omitted;  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.9.3.1.3  the responsible  person  shall  then wait for notification  from  the authorised  person  
by radio.  
8.3.9.3.2  The authorised  person  shall  then proceed  to the point  where  supply  is to be 
disconnected  and in conjunction  with the system  controller  have  the feeder  isolated  and 
earthed  and receive  a hand  out on the feeder.  
8.3.9.3.3  Once  the authorised  person  has had the feeder  handed  out to him or her, the 
authorised  person  shall  instruct  the responsible  person  to sign the work  permit,  fill in the 
time,  apply  working  earths  to the power  line and proceed  with the work  required.  
8.3.9.3.4.1  On completion,  the responsible  person  shall  remove  all working  earths,  sign off 
the work  permit  and report  back  to the authorised  person.  
8.3.9.3.4.2  The authorised  person  shall  sign his or her copy  of the work  permit  to 
acknowledge  that the responsible  person  has informed  him or her of the completion  of work.  
8.3.9.3.5  When  all the work  permits  issued  for the power  line have  been  cleared  or closed , 
the authorised  person  shall  hand  back  the circuit  to the system  controller.  
8.3.9.3.6.1  All communications  for work  in terms  of this section  shall  be done  over the 
telecommunication  system  of the licensee  and, if possible,  the messages  shall  be recorded.  
8.3.9.3.6.2  The completed  work  permit  shall  be returned  to the authorised  person,  who has 
issued  it, within  seven  days from  the date of issue.  
8.3.9.4  Work on a line at more than one place at the same time  
8.3.9.4.1  For work  at several  remote  points  on a line, which  has been  prepared  in accordance  
with this Standard,  the line may be handed  over to more  than one appointed  operator.  
8.3.9.4.2  The system  controller  shall  affix  on the operating  diagram/mimic  the name  of each 
appointed  operator  to whom  the line has been  handed  out. 
8.3.9.5  Work in close proximity to live conductors of a line  
8.3.9.5.1  If the activity,  task or action  is of such a nature  that it could  inadvertently  encroach  
on the minimum  safe working  clearance,  then this is interpreted  as close  proximity.  
8.3.9.5.2  If the minimum  safe working  clearance  between  persons,  machinery  or objects  and 
live apparatus  or lines  cannot  be maintained,  the live apparatus  or lines  shall  be isolated  and 
earthed  at a safety  panel.  
8.3.9.5.3.1  Where  work  is to be carried  out on the structure  of a line, the responsible  person  
may not work  on such structure  unless  he or she is supervised  by an appointed  operator,  who 
will ensure  that safe working  clearances  with respect  to live conductors  are maintained  at 
all times.  
8.3.9.5.3.2  The work  shall  only commence  after the system  controller  has handed  out the 
line to the appointed  operator.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.9.5.4  No breaker  controlling  the supply  to the line shall  be reclosed  after a breaker  trip 
until the system  controller  has confirmed  with the appointed  operator  to whom  the line has 
been  handed  out that it is safe to do so. 
8.3.9.5.5.1  No work  may be done  on one circuit  on a double  circuit  structure  if the other  
circuit  is alive.  
8.3.9.5.5.2  Work  may be done  on the line links  and the feeder  bay in the station,  after the 
equipment  has been  earthed  using  a special  technique,  as contained  in an operating  
procedure.  
8.3.9.6  Special precautions for lines with live conductors  
8.3.9.6.1  Work  may be carried  out by an authorised  person  on a pole or structure  which  
supports  conductors  alive  at medium  or high voltage  if the authorised  person  does not go 
above  ground/floor  level  and obtains  a hand  out. 
8.3.9.6.2  If a worker  is required  to work  on a structure  supporting  live conductors,  the worker  
shall  at all times  be under  the immediate  personal  supervision  of a responsible  person.  
8.3.10  Work on insulated conductors and underground cables  
8.3.10.1  Interference with conductors  
 No person  shall  interfere  with the insulation  that covers  or supports  any medium  or high 
voltage  conductor  unless  the conductor  has first been  isolated,  earthed  and handed  out to 
him or her. 
8.3.10.2  Cutting into cables  
8.3.10.2.1  Before  carrying  out any work  on medium  or high voltage  cables  which  involves  
cutting  into or removing  the insulated  covering  or earthed  metal  sheath  of the cable,  the 
authorised  person  in charge  of the work  shall  ensure  that the cable  is isolated,  earthed  at 
both ends where  possible  and identified.  
8.3.10.2.2  In all cases  where  there  is any doubt  as to identity,  the cable  shall  be spiked  with 
an approved  spiking  gun. 
8.3.11  Work  in stations  with  exposed  live conductors  
8.3.11.1  Live chambers  
8.3.11.1.1  Except  to the extent  necessary  for safety  testing  and earthing,  no person  shall  be 
permitted  to work  in a live chamber  until all apparatus  in that chamber  has been  isolated  and 
earthed.  
8.3.11.1.2  Capacitors  must  discharge  for at least 10 minutes.  
 
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All rights reserved  8.3.11.2  Prohibited areas  
8.3.11.2.1  Barriers  and clearances  
8.3.11.2.1.1  If a person  is required  to work  in a prohibited  area where  a hand  out or a work  
permit  is required,  unless  all apparatus  in that enclosure  have  been  made  safe, the section  
that has been  made  safe and earthed  for work  to be carried  out shall  be defined  as far as 
possible  by the use of barriers,  danger  tape or ropes  with warning  labels  where  deemed  
necessary.  
8.3.11.2.1.2  The barriers,  danger  tape or ropes  shall  be so arranged  that a worker  cannot  
come  within  the safe working  clearances  of live parts  from  any position  in which  the worker  
is permitted  by the barriers.  
8.3.11.2.2  Additional  precautions  
If, in the opinion  of the authorised  person  in charge  of the work,  the stated  safe working  
clearances  are not sufficient  to avoid  danger,  other  suitable  means  shall  be taken  to ensure  
the required  degree  of safety.  
8.3.11.2.3  Distinguishing  markers  
8.3.11.2.3.1  The section  that has been  made  safe for work,  shall  be distinguished  by having  
reflags  placed  on the non-working  side of the barriers,  danger  tape or ropes  at a distance  of 
0,5 m to 1,0 m from  the barriers,  danger  tape or ropes  and separated  by not more  than 6 m. 
8.3.11.2.3.2  The working  area may also be barricaded  with safety  nets. 
8.3.11.2.3.3  If work  is to take place  at night  and the lighting  conditions  are such that the red 
flags  cannot  be adequately  distinguished,  the flags  shall  be replaced  or supplemented  by red 
lights.  
8.3.12  Use of ladders and long objects  
8.3.12.1  Permission to use  
8.3.12.1.1  Ladders  and other  long objects  may not be used without  the permission  of the 
authorised  person  in charge  of the work.  
8.3.12.1.2  No metal  ladders  may be used in high voltage  yards.  
8.3.12.2  Type and size  
 Ladders  for use in a prohibited  area shall  be of an approved  type and may not be of an 
excessive  length  for the work  involved.  
8.3.12.3  Movement and erection  
8.3.12.3.1  The movement  and erection  of ladders  and long objects  shall  be carried  out under  
the immediate  personal  supervision  of a responsible  person.  
8.3.12.3.2  When  being  moved  at ground/floor  level,  they shall  be carried  in a horizontal  
position  and not above  waist  height.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.13  Metal clad switch gear  
8.3.13.1  Busbar spouts  
 When  work  is to be carried  out on busbar  spouts,  the following  operations  shall  be carried  
out in strict  sequence:  
8.3.13.1.1  The section  of the busbars  to be worked  on shall  be made  safe;  
8.3.13.1.2  all shutters  of live spouts  shall  be locked  so that they cannot  be opened.  If, because  
of the design  of the switch  gear,  it is not possible  to lock the shutters,  the authorised  person  
shall  take special  precautions  to mark  any spouts  that have  not been  made  safe for work;  
8.3.13.1.3  the busbars  shall  be tested  by means  of an approved  voltage  indicator  to verify  
that they are dead.  The voltage  indicator  itself  shall  be tested  before  and after use; 
8.3.13.1.4  the isolated  section  of the busbars  shall  be earthed  by means  of approved  earthing  
gear at a switch  gear panel  other  than the one at which  work  is to be done;  
8.3.13.1.5  the insertion  of the hand  or any tool apart  from  the approved  earthing  gear into 
the contact  spouts  for this purpose  is expressly  forbidden;  
8.3.13.1.6  warning  notices  shall  be attached  at all points  where  the busbars  can be made  
alive;  
8.3.13.1.7  a work  permit  or hand  out shall  be issued;  
8.3.13.1.8  working  earths  shall  be placed  in the contact  spouts  on all phases  of the busbars  
at the point  of work;  
8.3.13.1.9  the working  earths  may be removed  one phase  at a time when  necessary  for testing  
but shall  be replaced  as soon  as possible  and in any case before  the working  earth  on a 
second  phase  is removed,  unless  it is essential  for the test to have  more  than one working  
earth  removed.  
8.3.13.2  Feeder and voltage transformer spouts  
When  work  is to be carried  out on feeder  or voltage  transformer  spouts,  the following  
operations  shall  be carried  out in strict  sequence:  
8.3.13.2.1  The feeder  shall  be made  safe;  
8.3.13.2.2  the shutters  of all live spouts  on the circuit  shall  be locked  so that they cannot  be 
opened;  
8.3.13.2.3  if, because  of the design  of the switch  gear,  it is not possible  to lock the shutters,  
the authorised  person  shall  take special  precautions  to mark  any spouts  that have  not been  
made  safe for work;  
8.3.13.2.4  the circuit  shall  be tested  by means  of an approved  voltage  indicator  to verify  that 
it is not live; 
8.3.13.2.5  the voltage  indicator  itself  shall  be tested  before  and after use; PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.13.2.6  the circuit  shall  be earthed  by means  of approved  earthing  gear at all points  of 
isolation  from  the supply;  
8.3.13.2.7  the insertion  of the hand  or any other  tool apart  from  the approved  earthing  gear 
into the contact  spouts  for this purpose  is expressly  forbidden;  
8.3.13.2.8  warning  notices  shall  be attached  at all points  where  the circuit  can be made  
alive;  
8.3.13.2.9  a work  permit  or hand  out shall  be issued;  
8.3.13.2.10  the earths  may be removed  when  essential  for testing  purposes  but shall  be 
replaced  as soon  as possible.  
8.3.13.3  Removal of covers  
 No person  may remove  the covers  of any chamber  containing  live parts  until those  parts  
have  been  isolated,  safety  tested  and earthed  and, where  necessary,  a hand  out or work  
permit  issued.  
8.3.14  Work on transformers  
8.3.14.1  Isolation  
8.3.14.1.1  When  work  is to be carried  out on or in the proximity  of the conductors  of a 
transformer,  the isolators  for all windings  shall  be opened,  even  when  there  is no alternative  
source  of supply  to a winding.  
8.3.14.1.2  When  there  is a voltage  or auxiliary  transformer  associated  with the transformer,  
it shall  be isolated  or the low voltage  fuses  withdrawn  to prevent  the possibility  of the 
transformer  being  made  alive  through  the voltage  or auxiliary  transformer.  
8.3.14.2  Common neutral earthing equipment  
8.3.14.2.1  Where  the transformer  is connected  to neutral  earthing  equipment,  which  is also 
used by other  transformers,  the isolating  link between  the transformer  and the neutral  
equipment  shall  be opened  before  the transformer  is made  available  for work.  
8.3.14.2.2  The disconnection  of solidly  earthed  neutrals  or neutral  equipment  connected  
solely  to the transformer  on which  work  is to be carried  out, is not required.  
8.3.14.3  Neutral bushing  
 Where  work  is to be carried  out on the tank of a transformer  with an exposed  neutral  bushing,  
which  is not solidly  connected  to earth,  the transformer  must  be fully  isolated  and earthed.  
8.3.14.4  Tap changers  
8.3.14.4.1  Before  work  is carried  out on tap changer  mechanisms,  which  may operate  
automatically  or by remote  control,  all secondary  voltage  supplies  to the tap changer  shall  
be isolated.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.3.14.4.2  This requirement  does not exclude  tests and adjustments  on the mechanism  where  
the secondary  supplies  must  be connected  for the tests if all persons  working  on the 
equipment  are aware  of the situation.  
8.3.15  Testing of medium and high voltage equipment  
8.3.15.1  Person in charge  
8.3.15.1.1  When  any high voltage  apparatus  is to be subjected  to a test voltage  before  being  
connected  to the power  system,  the test shall  be carried  out under  the immediate  personal  
supervision  of an authorised  person.  
8.3.15.1.2  The authorised  person  shall  ensure  that such apparatus  is adequately  guarded  to 
prevent  danger  and that warning  notices  are attached  in conspicuous  places  for the duration  
of the test. 
8.3.15.2  Discharging of equipment  
8.3.15.2.1  All apparatus  shall  be discharged  before  and after the application  of the test 
voltage.  
8.3.15.2.2  Earths  shall  be reconnected  to all points  so connected  before  the test. 
8.3.15.3  Test conductors  
 Temporary  conductors  used for testing  purposes  shall  be adequately  rated  for the purpose  
and shall  be easily  visible.  
8.3.15.4  Test connections  
8.3.15.4.1  Test connections  shall  not be applied  in a compartment  where  there  are any 
exposed  live metal  parts  at medium  or high voltage  unless  the safe working  clearances  are 
maintained  between  the apparatus  to be tested  and the live metal  parts.  
8.3.15.4.2  This requirement  does not exclude  the use of approved  voltage  indicators  or 
approved  devices  for phasing  out circuits.  
8.3.16  Work on low voltage systems  
8.3.16.1  Step down medium to low voltage stations and pole mounted 
transformers  
8.3.16.1.1  A work  permit  shall  be issued  to a responsible  person  or contractor  before  any 
operating  is undertaken  on the low voltage  apparatus  in any stepdown  station  or on any pole 
mounted  transformer.  
8.3.16.1.2  The work  permit  shall  include  the details  of the work  to be undertaken  on the low 
voltage  system  and the appropriate  procedures  specified  in section  5 of this Standard  shall  
be followed  with the issuing  and clearance  of the work  permit.  
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All rights reserved  8.3.16.2  Low voltage power lines  
8.3.16.2.1.1  No person  shall  be allowed  to work  on live low voltage  power  lines  with 
exposed  conductors.  
8.3.16.2.1.2  The lines  shall  be isolated  and a work  permit  issued  as specified  in paragraph  
8.3.16.1  of this Standard.  
8.3.16.2.2.1  A person  who has been  trained  and authorised  to make  live connections  on 
insulated  aerial  bundle  conductor  power  lines,  may make  connections  on such power  lines  
without  a work  permit  being  issued  if such work  is carried  out using  approved  tools  and 
insulated  piercing  connectors.  
8.3.16.2.2.2  No other  work  may be carried  out on aerial  bundle  conductor  power  lines  
without  a work  permit  being  issued  and the feeder  being  isolated.  
8.3.16.3  Low voltage distribution kiosks  
8.3.16.3.1.1  No person  shall  be allowed  to undertake  work  in a low voltage  distribution  kiosk  
without  the supply  to the kiosk  either  being  isolated  at the point  of supply  or locally  in the 
kiosk  if facilities  have  been  provided  in the kiosk  for that purpose.  
8.3.16.3.1.2  Live work  may be undertaken  if suitably  rated  safety  gloves  are used.  
8.3.16.3.1.3  A work  permit  shall  be issued  and the appropriate  procedures  specified  in 
section  5 of this Standard  shall  be followed  prior  to the commencement  of the work.  
8.3.16.3.2.1  Meter  readers  shall  be allowed  access  to metering  kiosks  to read the consumer  
meters  if such meters  are installed  in a compartment  where  no live busbars,  conductors  or 
terminals  are exposed  or can be reached.  
8.3.16.3.2.2  The kiosks  shall  have  separate,  different  locks  for the metering  compartment  
and for the live compartment.  
8.3.16.3.3.1  A person  trained  and authorised  to do so, shall  be allowed  to disconnect  any 
consumer  from  the supply  for non payment  by switching  off the consumer  circuit  breaker.  
8.3.16.3.3.2  The person  shall  not be authorised  to isolate  the supply  by disconnecting  live 
conductors.  
8.3.16.3.3.3  Circuit  breakers  which  have  been  switched  off, for whatever  reason,  shall  be 
tagged  to indicate  that the circuit  has been  switched  off and that the circuit  has not tripped.  
8.4 Returning Feeders and Apparatus to Service  
8.4.1 Under normal conditions  
8.4.1.1  Before  returning  any feeder  or apparatus  to service  after work  carried  out thereon  
has been  completed,  the appointed  operator  shall  personally  be satisfied  that all persons  have  
been  withdrawn  from  the feeder  or apparatus  and from  all chambers  and enclosures  
containing  such apparatus  and that any permanent  barrier  have  been  re-installed.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.4.1.2  The appointed  operator  shall  advise  the system  controller  that the work  has been  
completed  and, where  applicable,  that all working  earths  have  been  removed  and that he or 
she is handing  back  the feeder  or apparatus.  
8.4.1.3  The system  controller  shall  remove  from  the feeder  or apparatus  on the operating  
diagram/mimic  the name  of the appointed  operator  and shall  issue  instructions  for the 
removal  of all other  earths.  
8.4.1.4  Where  a line has been  handed  to more  than one appointed  operator,  no earths  may 
be removed  from  the line until all appointed  operators  involved  have  reported  to the system  
controller  the completion  of their work  and the removal  of all working  earths  from  their 
portion  of the line. 
8.4.1.5  At power  stations,  when  work  is done  at more  than one place  in a circuit,  each work  
permit  shall  be cancelled  by the issue  of a clearance  on the completion  of each separate  item 
of the work  but no earths  may be removed  from  any portion  of the apparatus  until clearances  
have  been  received  for all work  permits  which  were  issued  for work  on the circuit.  
8.4.1.6  Before  finally  returning  the feeder  or apparatus  to service,  the appointed  operator  
must  ensure  that all affixed  warning  notices  have  been  removed.  
8.4.2 When the responsible person or appointed operator is not available  
8.4.2.1  If the responsible  person  to whom  a work  permit  has been  issued  is not available  to 
fill in and sign the clearance  on the work  permit  form  and to return  the work  permit  form  to 
the appointed  operator  concerned,  the official  in charge  shall  instruct  another  responsible  
person  to supervise  the completion  of the work  (if necessary)  and to fill in and sign the 
clearance  on the work  permit  form;  in which  case the other  responsible  person  shall  first 
countersign  the work  permit  application  to indicate  that he or she is fully  aware  of what  was 
to be done  on the apparatus.  
8.4.2.2  Whenever  it is necessary  to return  a feeder  or apparatus  to service  and the appointed  
operator  to whom  the feeder  or apparatus  has been  handed  out for work  is not available  for 
any reason,  the system  controller  shall  consult  with the official  in charge,  who shall  instruct  
another  appointed  operator  to return  the feeder  or apparatus  to service.  
8.4.2.3  In either  case the system  controller  shall  take all reasonable  steps  to ensure  that no 
danger  arises  from  such transfer  of responsibility.  
8.5 Exemption from General Procedure  
8.5.1 Work to be done on a line controlled from a single source of supply  
When  work  has to be done  by an appointed  operator  on a line on the distribution  system  
which  is controlled  from  a single  source  of supply,  the appointed  operator  may,  subject  to 
paragraph  4.5 of this Standard,  make  complete  prior  arrangements  with the system  controller  PRD/ SZNS  077: 202 3 
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All rights reserved  and may receive  pre-authorised  instructions  to open,  isolate  and earth  the line and 
subsequently  return  it to service  with the exception  that it will not be necessary  to advise  the 
system  controller  that work  has been  completed  before  the line is made  alive.  
8.5.2 Replacing of drop out fuse links without reference to the system 
controller  
8.5.2.1.1  An appointed  operator  may without  reference  to the system  controller  replace  one 
or two drop out fuse links  up to 33 kV on a three -phase  circuit,  when  found  blown,  but must  
replace  all three -phase  drop out fuse link fuses,  and may thereafter  close  the drop out fuse 
links  once  only.  
8.5.2.1.2  The appointed  operator  may not replace  the drop out fuses  if all three  fuses  are 
blown  unless  the consent  of the system  controller  has been  obtained.  
8.5.2.2.1  An appointed  operator  may without  reference  to the system  controller  replace  one 
fuse on a drop out fuse link up to 33 kV on a dual phase  circuit,  when  found  blown,  but must  
replace  both fuse link fuses,  and may thereafter  close  the drop out fuse links  once  only.  
8.5.2.2.2  The appointed  operator  may not replace  the drop out fuses  if both fuses  are blown  
unless  the consent  of the system  controller  has been  obtained.  
8.5.2.3  An appointed  operator  may not replace  the fuse of a drop out fuse link on a single - 
line circuit,  as on SWER  (single  wire earth  return)  reticulations,  when  found  blown,  but must  
first report  the situation  to the system  controller  for further  instructions.  
8.5.2.4.1  An appointed  operator  may not replace  blown  fuses  on drop out fuse links  on 
circuits  of 44kV  or higher,  unless  instructed  by the system  controller  to do so, in which  case 
only the blown  fuse or fuses  may be replaced  on sealed  type fuses.  
8.5.2.4.2  In the event  of a single  fuse being  blown  in a holder  with a replaceable  fuse element,  
all three  fuses  must  be replaced.  
8.5.2.5  The system  controller  shall  be notified  as soon  as possible  after the fuse has been  
replaced  and closed.  
8.5.3 Dual line  systems  
When  work  has to be done  by an authorised  person  on a dual line  system,  all lines  on the 
dual line  system  shall  be open,  isolated  and earthed  and handed  over in accordance  with this 
Standard  before  any work  may commence  on any of the lines.  
8.5.4 Station isolation  
8.5.4.1  Where  total station  isolation  is requested,  the station  shall  be isolated  and earthed  at 
all points  of supply.  
8.5.4.2.1  The station  shall  be handed  over to one authorised  person,  with permission  to apply  
and remove  working  earths  as required.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.5.4.2.2  The number  of working  earths  that were  applied  and removed  shall  be declared  at 
hand  back.  
8.6 Supervision of Work  
Responsible  persons,  contractors  or workers  shall  be responsible  for the execution  of all 
work  carried  out on apparatus  and feeders  in compliance  with this Standard.  
8.7 Temporary Absence of Persons in Charge of Work  
8.7.1.1  In the event  of an authorised  person  in charge  of any work  being  unable  to be present  
for the duration  of the work  in progress,  the authorised  person  shall,  in all cases,  before  
departing,  delegate  to another  authorised  person  to take charge  during  his or her absence.  
8.7.1.2  The system  controller  must  be informed  prior  to the departure  of the change  of 
responsibilities.  
8.7.2 Should  another  authorised  person  not be available,  all workers  shall  be withdrawn  from  
the work  during  the temporary  absence  of the authorised  person  in charge.  
8.8 Testing Apparatus  
8.8.1.1  Where  it is necessary  for tests to be carried  out on apparatus  by a responsible  person  
or a person  authorised  to do so, the system  controller  shall  issue  instructions  for the apparatus  
to be isolated  and earthed  in accordance  with this Standard,  after which  the system  controller  
shall  permit  the appointed  operator  to remove  the earth,  if necessary,  for such tests.  
8.8.1.2  Where  the appointed  operator  is not also the responsible  person,  the appointed  
operator  may only remove  such earth  under  the supervision  of the responsible  person.  
8.8.2.1  It shall  be the responsibility  of the person  carrying  out the tests to warn  and, where  
necessary,  to temporarily  withdraw  the workers  from  the apparatus  for the duration  of the 
tests.  
8.8.2.2  Upon  completion  of the tests,  the appointed  operator  shall  replace  the earth  and 
inform  the system  controller  that the apparatus  has been  restored  to the original  condition.  
8.8.3.1  If it is necessary  for the purpose  of carrying  out tests to energise  the apparatus  from  
the power  system  while  such apparatus  is in an abnormal  condition,  the responsible  person  
and the appointed  operator  must  make  special  arrangements  with the official  in charge  so 
that the operating  procedures  may be agreed  upon  beforehand.  
8.8.3.2  The agreed  operating  procedures  must  be carrie d out in accordance  with this 
Standard.  
8.8.3.3  For the purposes  of paragraph  8.8.3.1  of this Standard,  an abnormal  condition  is one 
in which  the apparatus  is not in a condition  to take normal  load due to jumpers  being  broken  
or temporary  connections  having  been  made,  or for some  similar  reason.  PRD/ SZNS  077: 202 3 
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All rights reserved  8.9 No Operating While Work is in Progress in Live Chamber  
Should  any operating  other  than emergency  switching  be necessary  at any station  on 
apparatus  in a live chamber  in which  inspection  or maintenance  work  is in progress,  all 
workers  shall  be withdrawn  from  the chamber  until such operating  has been  completed.  
9 Abnormal Conditions  
9.1 Abnormal Conditions to be Reported to System Controller  
The system  controller  must  be advised  as soon  as possible  of any failure  or interruption  of 
supply  to any part of a power  system,  or any abnormal  conditions  including  signs  of 
approaching  adverse  weather  conditions.  
9.2 Emergency Switching  
9.2.1 When  emergency  switching  has been  carried  out, all intended  work  shall  be suspended  
and immediate  attention  shall  be given  to the cause  of the emergency  switching  operation.  
9.2.2.1  Sole attention  must  be given  to injuries  sustained  by any person.  
9.2.2.2  Prompt  and effective  first aid must  be administered  by a competent  person  and the 
patient  must  be evacuated  and delivered  for professional  medical  treatment.  
9.2.3.1  The cause  must  be evaluated  and reported  to the system  controller.  
9.2.3.2  The system  controller  must  report  the matter  to all relevant  persons  involved  with 
incidents.  
9.2.3.3  Thereafter  the system  controller  may proceed  to attend  to the repair  or replacement  
of apparatus,  if necessary.  
9.2.4 Continuity  of supply  must  then be restored.  
9.3 Communication System  
9.3.1 Any message  to and from  the system  controller  shall  be given  preference  at all times  
in accordance  with paragraph  4.9 of this Standard.  
9.3.2 During  periods  of abnormal  conditions,  the system  controller  may interrupt,  or instruct  
any person  to defer  or interrupt,  calls or messages  other  than those  relating  to the control  of 
a power  system.  
9.4 Restoration of Supply in the Absence of Communication  
9.4.1.1  In cases  where  communication  with the system  controller  cannot  be established,  an 
appointed  operator  or authorised  person  may,  at his or her discretion,  close  breakers  in order  
to resume  supply . Provided  that where  two or more  feeders  enter  a station,  only the breakers  
of feeders  originating  from  one point  may be closed  without  permission  of the system  
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All rights reserved  9.4.1.2  The discretion  of the appointed  operator  or authorised  person  must  be led by the flags  
alarms  and the stability  of the power  system.  
9.4.2.1  The closing  of a breaker  to resume  supply  shall  be reported  to the system  controller  
as soon  as possible  thereafter.  
9.4.2.2  The operating  instruction  form  must  be duly completed.  
9.5 Establishment of Local Control Centre  
9.5.1 If necessary,  an authorised  person  may,  subject  to paragraph  9.5.2 of this Standard,  
establish  a local  control  centre  and take over the duties  of the system  controller  in respect  of 
the area affected.  
9.5.2 A local  control  centre  shall  not be established  until either  the system  controller  has 
given  permission,  or every  possible  effort  has been  made  to contact  the system  controller  but 
has failed  and all appointed  operators,  who are operating  in the area affected,  have  been  
advised  of the establishment  of the local  control  centre.  
9.5.3 All operating  must  be logged  during  this period,  and when  communication  or normal  
conditions  are restored,  the system  controller  must  be given  full details  of the operating  as 
well as the positions  of all breakers,  links  and earthing  gear at the time of handing  back  to 
the system  controller.  
9.5.4 The authorised  person  in charge  of the local  control  centre  shall  be responsible  for the 
operation  of the section  of the power  system  located  in the area affected  in accordance  with 
this Standard,  but may not personally  carry  out any operating.  
10 Live Work  
10.1 Abnormal Conditions to be Reported to System Controller  
10.1.1  Persons in charge of live work  
 Only  persons  who have  been  specifically  authorised  to be in charge  of live work  shall  take 
over live apparatus  for live working  and issue  a live work  declaration  form.  
10.1.2  Persons who may perform live work  
10.1.2.1 Subject  to paragraph  10.1.2.2 of this Standard,  live work  may only be performed  
by persons  who have  been  specifically  authorised  to do so. 
10.1.2.2 Unauthorised  persons  may be permitted  to perform  live work  while  undergoing  
training  if such persons  are under  supervision  of an instructor,  who has been  authorised  to 
perform  live work.  
10.1.3  Persons who may deputise for the responsible person  
 Only  an authorised person  may take over the responsibilities  of the responsible person  for 
purposes  of completing  the specific  task.  PRD/ SZNS  077: 202 3 
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All rights reserved  10.2 Live Work at Power Stations or on the Distribution System  
10.2.1  Circumstances requiring a live work declaration form  
 A live work  declaration  form  shall  be required  for all live work  on a minimum live medium - 
voltage  apparatus  at any power  station  or at any place  on the transmission  system  or 
distribution  system.  
10.2.2  Forms  in duplicate  
10.2.2.1 A live work  declaration  form  shall  be made  out in duplicate.  
10.2.2.2 The original  shall  be retained  by the authorised  person  in charge  of the live work  
and the copy  shall  be left in the live work  declaration  book.  
10.2.3  Preparation and handing over of apparatus for live work  
10.2.3.1 When  live work  is to be carried  out on any high voltage  apparatus,  the authorised  
person  in charge  of the live work  shall  notify  the system  controller  of the following:  
10.2.3.1.1  The apparatus  to be worked  on; 
10.2.3.1.2  the nature  of the work  to be carried  out; 
10.2.3.1.3  the time that the work  is to commence  and the estimated  duration  of the work.  
10.2.3.2 The authorised  person  in charge  of the live work  shall  arrange  with the system  
controller  for live work  warning  notices  to be affixed  to all control  panels  of breakers  
controlling  the supply  to the apparatus  concerned  and for all auto-reclosing  features  on such 
breakers  to be switched  off or otherwise  made  inoperative.  
10.2.3.3.1  Where  the auto-reclose  function  of a line is made  inoperative  via supervisory  
remote  control,  it is not necessary  to apply  a live work  warning  notice  to the control  panel.  
10.2.3.3.2  If the auto-reclose  is made  inoperative  manually,  the live work  warning  notice  
shall  be applied.  
10.2.3.3.3  All SCADA  controls  to the affected  circuit  shall  be made  inoperative.  
10.2.3.4 When  live work  warning  notices  have  been  affixed  to all control  panels  of breakers  
controlling  the supply  to the apparatus  concerned  and all auto-reclosing  features  on these  
breakers  have  been  switched  off or made  inoperative,  the system  controller  shall  so inform  
the authorised  person  in charge  of the live work  and shall  hand  over the apparatus  to the 
responsible person . 
10.2.3.5.1 This must  be recorded  by the system  controller  and all SCADA  controls  to the 
affected  circuit  shall  be made  inoperative.  
10.2.3.5.2 It will not be necessary  to apply  the live work  warning  notice  if all work  is done  
in strict  accordance  with the approved  high voltage  live working  standards  and procedures.  PRD/ SZNS  077: 202 3 
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All rights reserved  10.2.4  Issue of a live work declaration form  
10.2.4.1.1  The responsible person  to whom  the system  controller  has handed  over apparatus  
for live work,  shall  explain  to all the persons  who will be engaged  in the live work  the 
arrangements  made  with the system  controller.  
10.2.4.1.2  The authorised  person  in charge  of the live work  shall  identify  the apparatus  to be 
worked  on, the operational  voltage  of the apparatus  to be worked  on and the corresponding  
safe working  clearance  to be maintained.  
10.2.4.2 The persons  to be engaged  in the live work  shall  acknowledge  their understanding  
of these  details  and restrictions  by signing  the live work  declaration  form  before  they proceed  
with the live work.  
10.2.5  Cancellation or Closing of a live work declaration form  
10.2.5.1.1  When  live work  has been  completed,  or is suspended  for any reason,  and the 
apparatus  is to be returned  to normal  service,  the authorised  person  in charge  of the live work  
shall  withdraw  all persons  from  the live apparatus.  
10.2.5.1.2  The authorised  person  in charge  of the live work  shall  remove  all tools  and 
equipment  to a safe position  in relation  to the live apparatus.  
10.2.5.2 The authorised  person  in charge  of the live work  shall  advise  the persons  engaged  
in the live work  that the apparatus  is to be handed  back  to the system  controller  and that no 
further  work  may be performed.  
10.2.5.3 The authorised  person  in charge  of the live work  shall  notify  the system  controller  
that the live work  is complete  or otherwise  of the exact  state of the apparatus  and whether  
tools  or equipment  have  been  left on the apparatus.  
10.2.5.4 The authorised  person  in charge  of the live work  shall  complete  and sign the 
clearance  section  on the original  and duplicate  live work  declaration  form.  
10.2.6  Original and duplicate forms  
 Original  live work  declaration  forms  and completed  books  shall  be retained  for the period  
determined  by the licensee.  
10.2.7  Restrictions on re -closing breakers  
10.2.7.1 When  the system  controller  has handed  over any apparatus  for live work,  the name  
of the responsible person  shall  be affixed  to the operating  diagram/mimic  in the control  
centre.  
10.2.7.2 No operating  other  than the emergency  opening  of breakers  shall  be performed  on 
the breakers  controlling  supply  to the apparatus  until the authorised  person  in charge  of the 
live work  has handed  back  the apparatus  to the system  controller.  PRD/ SZNS  077: 202 3 
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All rights reserved  10.2.7.3 From  the time that the apparatus  is handed  over to the time that the apparatus  is 
handed  back  to the system  controller,  no breaker  which  controls  the supply  to the apparatus  
and which  has tripped  for whatever  reason,  shall  be reclosed  until such time as the authorised  
person  in charge  of the live work  has contacted  the system  controller  and has stated  that it is 
safe for the breaker  to be reclosed.  
10.2.8  Duration of live work declaration  
 It is the responsibility  of the responsible person  to decide  when  conditions  are such that live 
work  can no longer  proceed  safely,  whereupon  the live work  declaration  shall  be cancelled  
or closed  in accordance  with paragraph  10.2.5 of this Standard.  
10.2.9  When the responsible person  is not available  
10.2.9.1 If the authorised  person  to whom  apparatus  has been  handed  out is for any reason  
not available,  another  person  authorised  in terms  of paragraph  10.1.1 or 10.1.2 of this 
Standard  may take over the responsibilities  of the authorised  person  in charge  of the live 
work.  
10.2.9.2 This person  shall  countersign  the original  of the live work  declaration  form  to 
indicate  that he or she is fully  aware  of what  must  be done  on the apparatus  and inform  the 
system  controller  that he or she has taken  over the apparatus.  
10.2.9.3 The system  controller  shall  remove  the name  of the original  authorised  person  from  
the operating  diagram/mimic  in the control  centre  and shall  record  the name  of the authorised  
person  then in charge  of the live work.  
10.3 Supervision of Live Work  
10.3.1 The responsible person  shall  be responsible  for the safe execution  of live work.  
10.3.2.1 The responsible person  shall  at all times  observe  the work  in progress  to ensure  that 
it is carried  out in a safe manner.  
10.3.2.2 When  the responsible person  needs  to withdraw  from  the workplace,  another  person  
authorised  in terms  of paragraph  10.1.2 of this Standard  shall  take charge  of the live work  
and shall  observe  the live work  in progress  to ensure  that it is carried  out in a safe manner.  
10.3.3 Where  the responsible person  cannot  observe  part of the work,  the observation  of that 
part of the work  shall  be delegated  to another  person  authorised  in terms  of paragraph  10.1.2 
of this Standard.  
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All rights reserved  11 Design and Construction  
11.1 General  
This section  covers  the safety  aspects  and standards  to be taken  into account  in the design  
and construction  of power  lines.  
11.2 Normative Standards  
The following  standards  should  be taken  into account  in the design  and construction  of power  
lines:  
11.2.1 SANS standards:  
11.2.1.1  SANS  088: Pile foundations.  
11.2.1.2  SANS  0100 -1: The structural  use of concrete  – Part 1: Design.  
11.2.1.3  SANS  0100 -2: The structural  use of concrete  – Part 2: Materials  and execution  of 
work.  
11.2.1.4  SANS  0120 -3-HC: Standard  of practice  for use with standardized  specifications  for 
civil engineering  construction  and contract  documents  – Part 3: Guidance  for design  – 
Section  HC: Corrosion  protection  of structural  steelwork.  
11.2.1.5  SANS  0121:  Cathodic  protection  of buried  and submerged  structures.  
11.2.1.6  SANS  0162 -1: The structural  use of steel – Part 1: Limit -states  design  of hot-rolled  
steelwork  
11.2.1.7  SANS  0162 -2: The structural  use of steel – Part 2: Limit -states  design  of cold-
formed  steelwork.  
11.2.1.8  SANS  0163 -1: The structural  use of timber - Part 1: Limit -states  design.  
11.2.1.9  SANS  0199:  The design  and installation  of an earth  electrode.  
11.2.1.10  SANS  1200 -F: Standardized  specification  for civil engineering  construction  – 
Section  F: Piling.  
11.2.1.11  SANS  1200 -G: Standardized  specification  for civil engineering  construction  – 
Section  G: Concrete  (structural).  
11.2.1.12  SANS  1200 -HC: Standardized  specification  for civil engineering  construction  – 
Section  HC: Corrosion  protection  of structural  steelwork.  
11.2.1.13  SANS  IEC 60383 -1: Insulators  for overhead  lines  with a nominal  voltage  above  1 
000 V – Part 1: Ceramic  or glass  insulator  units  for AC systems  - Definitions,  test methods  
and acceptance  criteria.  
11.2.1.14  SANS  IEC 60815:  Guide  for the selection  of insulators  in respect  of polluted  
conditions.  
11.2.1.15  SANS  10280 - Overhead  power  lines  for conditions  prevailing  in South  Africa.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.2.2 IEC standards:  
11.2.2.1  IEC 60071 -1: Insulation  co-ordination  – Part 1: Definitions,  principles  and rules.  
11.2.2.2  IEC 60071 -2: Insulation  co-ordination  - Part 2: Application  guide.  
11.2.2.3  IEC 60826:  Loading  and strength  of overhead  transmission  lines.  
11.2.3 NRS standards:  
11.2.3.1  NRS  000: Rationalized  user definitions  for use in the Electricity  Supply  Industry.  
11.2.3.2  NRS  001: Cost of Supply  methodology.  
11.2.3.3  NRS  002: Graphical  symbols  for electrical  diagrams.  
11.2.3.4  NRS  034: Electricity  Distribution  – Guidelines  for the application  design,  planning  
and construction  of medium  voltage  overhead  power  lines  up to and including  22kV,  using  
wooden  pole structures  and bare conductors.  
11.2.3.5  NRS  034: Guidelines  for the provision  of electrical  distribution  networks  in 
residential  areas.  
11.2.3.6  NRS  040: High voltage  operating  regulations.  
11.2.3.7  NRS  043: Standard  of practice  for the joint use of structures  for power  and 
telecommunication  lines.  
11.2.3.8  NRS  044: Working  procedures  and standards  in respect  of the installation  of new 
electrical  works  and telecommunication  facilities,  or the extension  or modification  of such 
existing  works  and facilities.  
11.2.3.9  NRS  047: Quality  of service.  
11.2.3.10  NRS  048: Quality  of supply.  
11.2.3.11  NRS  057: Standard  of practice  for electricity  metering.  
11.2.3.12  NRS  060: Standard  of practice  for clearances  for electrical  systems  with rated  
voltages  up to and including  145kV,  for safety  reasons.  
11.2.3.13  NRS  064: Guideline  for the exchange  of spatial  information  in the Electricity  
Supply  Industry.  
11.2.3.14  NRS  069: Standard  of practice  for the recovery  of capital  costs  for distribution  
network  assets.  
11.2.3.15  NRS  076: Earthing  of distribution  substations  with nominal  voltages  up to and 
including  132kV.  
11.2.3.16  NRS  080: Quantifying  and reporting  of energy  losses  in electricity  distribution  
networks.  
11.2.3.17  NRS  082: Recommended  maintenance  policy  for electricity  networks.  
11.2.3.18  NRS  089 - 1: Maintenance  of electricity  networks  – Part 1: Power  cables.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.2.3.19  NRS  089 – 2 - 1: Maintenance  of electricity  networks  - Part 2: Overhead  
distribution  systems,  Section  1: Overhead  lines.  
11.2.3.20  NRS  089 – 2 - 2: Maintenance  of electricity  networks  – Part 2: Overhead  
distribution  systems,  Section  2: Inspection  and supplemental  of treated  wood  utility  poles.  
1.2.3.21  NRS  089 - 2 - 3: Maintenance  of electricity  networks  – Part 3: Overhead  distribution  
systems,  Section  3: The manual  replacement  of a rotten  wooden  pole structure.  
11.2.3.22  NRS  089 - 2 - 4: Maintenance  of electricity  networks  - Part 4: Overhead  
distribution  systems,  Section  4: Clearing  and maintenance  of servitude  routes.  
11.2.3.23  NRS  089 - 2 - 5: Insulators.  
11.2.3.24  NRS  089 - 3.1: Maintenance  of electricity  networks  – Part 3: Power  substation,  
Section  1: General.  
11.2.3.25  NRS  089 - 3.2: Maintenance  of electricity  networks  – Part 3: Power  substation,  
Section  2: Power  transformers,  Circuit  breakers,  isolators  and instrument  transformers.  
11.2.3.26  NRS  089 - 3.3: Maintenance  of electricity  networks  – Part 3: Power  substation,  
Section  3: Miniature  substations,  distribution  transformers  and electrical  enclosures.  
11.2.3.27  NRS  089 - 4: Maintenance  of electricity  networks  – Part 4: Control  technologies.  
11.2.3.28  NRS  089 - 5 - 2: Maintenance  of electricity  networks  - Part 5: Street  and area 
lighting,  Section  2: Street  lighting.  
11.2.3.29  NRS  089 – 5 - 3: Maintenance  of electricity  networks  – Part 5: Street  and area 
lighting,  Section  3: High  mast.  
11.3 Equipment and Material  
 Material  and equipment  to be used on power  lines  shall  comply  with the latest  applicable  
standard  specifications.  
11.4 Clearances of Power Lines  
11.4.1  Minimum clearances to other services  
 The minimum  clearances  of electric  conductors  and other  wires  of power  lines  to other  
services  shall  not be less than the clearances  indicated  in the following  table,  Table 1:  
 
 
 
 
 
 
 
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All rights reserved  Table  1: Minimum  clearances  to other  services   
 MINIMUM CLEARANCE IN METERS  
Highest 
system  
RMS 
voltage 
phase -to-
phase  
kV System 
nominal  
RMS  
voltage 
kV Above 
ground 
outside 
townships  Above 
ground in 
townships  Above 
roads in 
townships, 
proclaimed  
roads 
outside 
townships 
and 
railways  To communication 
lines, other power 
lines or  between 
power  lines To structures not 
forming  
part of power 
lines 
1,1 or
 less - 4,9 5,5 6,1 0,6 3,0 
7,2 6.6 5,0 5,5 6,2 0,7 3,0 
12 11 5,1 5,5 6,3 0,8 3,0 
24 22 5,2 5,5 6,4 0,9 3,0 
36 33 5,3 5,5 6,5 1,0 3,0 
48 44 5,4 5,5 6,6 1,1 3,0 
72 66 5,7 5,7 6,9 1,4 3,2 
100 88 5,9 5,9 7,1 1,6 3,4 
145 132 6,3 6,3 7,5 2,0 3,8 
245 220 6,7 6,7 7,9 2,4 4,2 
300 275 7,2 7,2 8,4 2,9 4,7 
362 330 7,8 7,8 9,0 3,5 5,3 
436 400 8,1 8,1 9,3 3,8 5,6 
800 765 10,4 10,4 11,6 6,1 8,5 
533 kV
 DC  8,6 8,6 4,3 4,3 6,1 
Note: protection of wild life and special areas  
Provided  that these  figure  are based  on the assumption  that clearances  shall  be determined  
for a minimum  conductor  temperature  of 50C and a swing  angle  corresponding  to a wind  
pressure  of 500Pa:  Provided  further  that where  under  normal  conditions  power  line 
conductors  operat e  at a temperature  above  50 CC, the clearance  at the higher  temperature  
at which  the conductors  operate  shall  be in accordance  with the clearance  indicated  in Table 
1. For the purposes  of Table 1:  
(a) Minimum  clearance  above  ground  in and outside  townships  means  the minimum  distance  
between  live parts  of apparatus  and earth;   
(b) Minimum  clearance  above  roads  and railways,  in and outside  townships  means  the 
minimum  distance  between  live parts  of apparatus  and such roads  and railways;   PRD/ SZNS  077: 202 3 
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All rights reserved  (c) Minimum  clearance  between  power  lines  and communication  lines  means  the minimum  
distance  between  live conductors  and such lines;   
(d) Minimum  clearance  to structures  not part of power  lines  means  the minimum  distance  
between  live conductors  and such structures.   
11.4.2  Standard Minimum Electrical Clearances/Distances  
The standard  minimum  electrical  clearances/distances  shall  not be less than the 
clearances/distances  indicated  in the following  table,  Table 2:  
Table 2:  Standard minimum electrical clearances/distances  
System 
nominal  
voltage  
kV Highest  
system  
voltage  
kV Minimum 
electrical 
clearance/distance  
in mm  Minimum safe 
working clearance/ 
distance  
in mm  Minimum live 
work safe working  
clearance/distance  
in mm  
RMS  Peak Phase -
to-earth Phase -
to-
phase  Vertical  Horizontal  Phase -
to-earth Phase -
to-
phase  
1 1.5 15 20 20 20 - - 
3.3 3.6 80 110 2500 1200 500 950 
6.6 7.2 150 200 2600 1200 600 1100 
11 12 200 300 2700 1300 700 1100 
22 24 320 400 2800 1400 800 1100 
33 36 430 500 2900 1500 800 1100 
44 48 540 610 3000 1600 800 1100 
66 72 770 890 3200 1800 900 1300 
88 100 1000 1140 3300 1900 1000 1500 
132 145 1450 1680 3700 2300 1200 1900 
220 245 1850 2700 4300 2900 1700 2800 
275 300 2100 3600 4800 3400 2000 3400 
330 362 2500 4300 5400 4000 2300 4100 
400 436 2900 4800 5700 4300 2800 4800 
765 800 3200 8900 8500 7100 5500 9700 
533 kV D.C. 3700 n/a 6200 5900 4250 - 
For the purposes  of Table  2: 
(a) Minimum  electrical  clearance  means  the minimum  distance  in clean  dry air, between  
different  live parts  of apparatus  or live parts  and earth  required  to ensure  that the 
possibility  of electrical  breakdown  is negligible;   PRD/ SZNS  077: 202 3 
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All rights reserved  (b) Minimum  safe working  clearance  means  the minimum  distance,  vertically  or 
horizontally,  that must  be maintained  between  any body  part of a person,  or a conductive  
tool directly  handled,  and live parts  of apparatus  at different  potential;   
(c) Minimum  live work  working  clearance  means  the minimum  distance  between  phase -to-
earth  and phase -to-phase.   
11.4.3  Minimum Safety Clearances  
The minimum  safety  clearances  shall  not be less than the clearances  indicated  in the 
following  table,  Table 3 : 
Table 3:  Minimum safety clearances   
Highest 
system 
RMS 
voltage  
kV System 
nomina
l 
RMS  
voltage 
kV Safety 
clearanc
e 
phase -to-
earth m  Safety 
clearanc
e 
phase -
to- 
phase m  Minimum live 
line working 
clearances  
m Tower -top clearances  
m 
Phase
-to-
earth  Phase
-to-
phase  Still air  
condition
s Norma
l swing  Maximu
m swing  
1.1 or
 less - - - - - - - - 
7,2 6.6 0.15 0.2 - - - - - 
12 11 0.2 0.3 - - - - - 
24 22 0.32 0.4 - - - - - 
36 33 0.43 0.5 - - - - - 
48 44 0.54 0.61 0.8 1.1 0.54 0.5 0.15 
72 66 0.77 0.89 0.9 1.3 0.77 0.71 0.2 
100 88 1.00 1.14 1.0 1.5 1.00 0.92 0.24 
145 132 1.45 1.68 1.2 1.9 1.45 1.3 0.35 
245 220 2.1 2.7 1.7 2.8 2.1 1.88 0.6 
300 275 2.5 3.6 2.0 3.4 2.5 2.2 0.7 
362 330 2.9 4.3 2.3 4.1 2.9 2.6 0.86 
436 400 3.2 4.8 2.8 4.8 3.2 2.9 1.0 
800 765 5.5 8.9 5.5 9.7 5.5 5.2 1.9 
533
 
kV
 
DC  3.7 -      
 
 
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All rights reserved  11.4.4  Clearances between parallel independent structures  
11.4.4.1 The separation  between  an overhead  communication  line and a power  line or two 
power  lines  erected  parallel  to each other  along  the same  route,  shall  be such that the 
clearance  between  any conductor  of the higher  voltage  line and any conductor  or earth  wire 
of the lower  voltage  line is never  less than the minimum  phase -to-phase  clearance  applicable  
to the higher  voltage  line. 
11.4.4.2.1 The separation  between  parallel  lines  shall  be such that, should  either  line 
overturn,  it will not touch  any part of the adjacent  line. 
11.4.4.2.2 If this separation  cannot  be provided,  the supports  of the line that could  touch  the 
other  line shall  be designed  to withstand  the broken -wire condition.  
11.4.5  Clearances between circuits on common structures  
11.4.5.1 The higher  voltage  line shall  be above  the lower  voltage  line or communication  line 
where  lines  are erected  one above  the other  on common  structures , with the exception of 
Optic al Ground Wire (OPGW) . 
11.4.5.2 The vertical  separation  between  the nearest  conductors  of any two lines  shall  be in 
accordance  with the phase -to-phase  clearances  given  in Table  I for the higher  voltage  line. 
11.4.6  Clearances between conductors of lines with  a vertical configuration  
 Attention  to ensure  compliance  with the phase -to-phase  voltage  clearances  where  a higher -
mounted  conductor  could  operate  at full load and maximum  sag with a lower -mounted  
conductor  at ambient  temperature.  
11.4.7  Aerial bundle conductors  
 An aerial  bundled  conductor  may be considered  to be an insulated  cable  for determining  
clearances.  Ground clearance is 7.5m.  
11.4.8  Induced voltages  
The distance  between  the power line and any other  system  (such  as a telecommunication,
railway  or pipeline)  shall  be such that induced  voltages  shall  not exceed:  
11.4.8.1  a RMS  voltage  of 50V in steady  operational  state;   
11.4.8.2  a RMS  voltage  of 430V  on power  lines  where  an earth  fault is cleared  in more  than 
0,5s;  
11.4.8.3  a RMS  voltage  of 650V on power  lines  where  an earth  fault is cleared  in 0,35s  to 
0,5s:  or 
11.4.8.4 a RMS  voltage  of 1 200V  on power  lines  where  an earth  fault is cleared  in less than 
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All rights reserved  11.4.9  Electrolytic corrosion  
11.4.9.1.1 Where  a risk exists  of electrolytic  corrosion  of underground  services  in the 
proximity  of a power  line due to stray  currents  from  DC services  entering  the earthing  
system  of a power  line erected  close  to the DC service,  suitable  protective  measures  shall  be 
taken  to reduce  the risk of electrolytic  corrosion.   
11.4.9.1.2 This will usually  take the form  of separating  the earthing  system  from  the DC 
system  and providing  interposing  insulating  material.   
11.4.9.2 Corrosion  protection  measures  shall  comply  and must  be developed  with due 
recognition  of SANS  1200 -HC, SANS  0120 -3-HG and SANS  0121.  
11.5 Conductors and Earth Wires for Power Lines  
11.5.1  Corrosion  
 All conductors  and earth  wires  shall  be of materials  that have  adequate  corrosion  resistance  
to the atmosphere  to which  they are likely  to be exposed  in service,  or shall  be suitably  
protected  against  corrosion.  
11.5.2  Minimum size  
11.5.2.1  The minimum  size of the conductor  or the conductor  bundle  shall  be determined  by 
the following  key factors:  
11.5.2.1.1  The thermal  rating  that is required;  and 
11.5.2.1.2  the short -circuit  current.  
11.5.2.2  The size of the phase  single  conductor  or of the phase  bundle  shall  be selected  to 
limit  voltage  drop,  audible  noise,  radio  interference,  television  interference  and loss due to 
corona.  
11.5.3  Current -carrying capacity  
11.5.3.1  The following  are the three  main  operational  states  for which  current -carrying  
capacity  calculations  can be done:  
11.5.3.1.1  Long  duration/normal  operation:  it is preferable  to limit  the conductor  temperature  
to between  50°C  and 60°C;  
11.5.3.1.2  emergency  operation:  where  it is expected  that normal  current -carrying  capacity  
will be exceeded;  
11.5.3.1.3  short -duration  emergency  operation:  where  temperatures  exceeding  80°C  are 
assumed,  the thermal  behaviour  shall  be assumed  not to change.  
11.5.3.2  In the case of copper  conductors,  the normal  operating  temperature  limits  should  
not be exceeded.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.5.4  Maximum tensions  
11.5.4.1  The maximum  tension  in conductors  and earth  wires  at a temperature  of -5°C and a 
wind  pressure  of 700 Pa on a shape  factor  of 0,6 of the projected  area should  not exceed  40% 
of the breaking  strength  of the conductors  or earth  wires.  
11.5.4.2  If there  is a possibility  of conductor  vibration  which  could  lead to the failure  of the 
conductor  due to fatigue,  the risk should  be reduced  by using  a lower  conductor  tension  than 
the maximum  permitted.  
11.5.4.3  The tension  limits  for conductors  and steel earth  wires  are as follows:  
11.5.4.3.1  Copper  conductors:  The tension  at a temperature  of 15°C  should  not exceed  26% 
of the ultimate  tensile  strength  of the conductor;  
11.5.4.3.2  ACSR  and AAAC  conductors:  If vibration  dampers  are not used and the lines  
have  relatively  short  spans,  typically  under  200 m, the initial  tension  at a temperature  of - 
5°C should  not exceed  25% of the ultimate  tensile  strength  of the conductor.  When  vibration  
dampers  are used,  the following  limitations  are recommended:  
11.5.4.3.2.1The  initial  tension  at -5°C should  not exceed  33,3%  of the ultimate  tensile  
strength  of the conductor;  
11.5.4.3.2.2  the initial  tension  at 15°C  should  not exceed  25% of the ultimate  tensile  strength  
of the conductor;  and 
1.5.4.3.2.3  the final tension  at 15°C  should  not exceed  20% of the ultimate  tensile  strength  
of the conductor;  
11.5.4.3.3  earth  wires:  In the case of galvanized  steel earth  wires  of minimum  breaking  
strength  in the range  700 MPa  to 1 100 MPa,  the maximum  tension  at 15°C  should  be such 
that the stress  in the earth  wire does not exceed  180 MPa.  This criterion  permits  the use of 
tensions  (at 15°C)  of the following  percentages  of minimum breaking  strength:  
11.5.4.3.3.1  700 MPa  wires:  25%;  and 
11.5.4.3.3.2  1 100 MPa  wires:  15%.  
11.5.5  Sag charts  
 Sag information  and the correction  table  for increased  time between  stringing  and regulating  
should  be obtained  from  the manufacturer  of the chosen  conductor  in order  to produce  sag 
charts.   
11.5.6  Creep  
 Initial  (or stringing)  charts  and final charts  in which  a maximum  allowance  is made  for 
creep  should  be prepared  before  stringing  commences.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.5.7  Joints  
11.5.7.1.1  All joints  shall  be such that their current -carrying  capacity  exceeds  that of the 
conductors  that are being  joined.  
11.5.7.1.2  Tension  joints  shall  have  a breaking  strength  of at least 95% of that of the 
conductor.  
11.5.7.2  In areas  that are conducive  to corrosion,  it is good  practice  to coat the joined  ends 
and fill the fittings  with chemically  inert corrosion -inhibiting  paste.  
11.6 Power Line Structures  
11.6.1  Factors of safety  
 The minimum  factors  of safety  to be applied  for the type of structure  and load are indicated  
in the following  table,  Table 4 : 
Table 4:  Minimum factors of safety  
Type of structure   Factor of safety  
Based on 
type-tested 
structure  Based on 
ultimate  
breaking 
strength  Based on 
modulus of  
rupture  
Steel  lattice  structures  and cross -arms 2.5 2.5  
Solid -drawn  steel poles  2.0 2.5  
Welded  steel poles  and steel poles  with swaged  or 
telescopic  joints  2.2 2.5  
Stay-wire assemblies   2.5 2.5  
Reinforced  concrete  spun  poles  2.4 3.5  
Mechanically  vibrated  reinforced  concrete  structures  
and components  2.5 3.5  
Other  types  of reinforced  concrete  structures  and 
components  2.75 3.75  
Wooden  members  not continuously  loaded  3.5 4.4 2.7 
Wooden  members  subjected  to continuous  Loading  5.5 6.75 4.5 
In the case of steel lattice  structures  and steel components  such as built-up cross -arms  and 
bracing  members,  the factor  of safety  shall  be 2,5 on tested  failing  load or, when  calculated,  
on tensile  strength  of tension  members  and on crippling  strength  of compression  members.  
11.6.2  Design Loading  
 The total load on a support  consists  of the following  loads,  which  should  be taken  into 
consideration  with the design  of the support:  PRD/ SZNS  077: 202 3 
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All rights reserved  11.6.2.1  Wind  loads  on conductors  and earth  wires;  
11.6.2.2  wind  loads  on supports;  
11.6.2.3  wind  loads  on insulators  and fittings;  
11.6.2.4  vertical  loads  due to conductors;  
11.6.2.5  vertical  loads  due to supports,  insulators  and fittings;  
11.6.2.6  normal  loads  due to conductor  tensions;  
11.6.2.7  loads  due to differential  tension;  
11.6.2.8  horizontal  loads  due to stay wires.  
11.6.3  Loading due to broken conductors  
 With  a line that has a single  conductor  per phase,  the assumptions  given  in the following  
table,  Table  5, in respect  of the loads  imposed  on the structures  that support  the span in 
which  the break  occurs,  expressed  as percentages  of the maximum  design  load at a 
temperature  of -5°C and when  subjected  to a wind  pressure  of 700 Pa, can be used for the 
design  loading  of a structure.  
Table 5:  Loads imposed on structures owing to conductor breakage  
Type of structure  Load imposed on structure, as a percentage of 
maximum design load  
Conductor attachment point  Earth wire attachment point  
Strain  100 100 
Suspension  70 100 
11.6.4  Erection loads  
 When  a design  does allow  for the conductors  and earth  wires  to be strung  on one side only 
of a strain  structure,  the design  should  allow  for the following  conditions:  
11.6.4.1  The conductor  tension  during  erection  would  normally  be that at about  15°C  in still 
air and the strain  structure  should  be capable  of withstanding  the load due to this tension,  
with a factor  of safety  of 1,5; 
11.6.4.2  when  the structure  is strung  on one side only,  the structure  should  be capable  of 
withstanding  the load due to conductor  tension,  at a temperature  of -5°C and when  subjected  
to a wind  pressure  of 700 Pa, with a nominal  factor  of safety  of, say, 1,2 during  erection  
conditions;  
11.6.4.3  all structures  should  furthermore  be capable  of withstanding,  with a factor  of safety  
of 1,5, the normal  vertical  loads  plus an additional  mass  of 150 kg to 300 kg to allow  for the 
weight  of the workers  and their equipment  at each conductor  attachment  point  during  
construction  and the vertical  component  of loads  due to back  staying  should  also be 
considered.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.7 Foundations for Power Line  
11.7.1 Structures  erected  on concrete  foundations  in the case of lattice  steel structures  or 
directly  in the ground  in the case of wooden,  concrete  or steel poles  shall  be so set in the 
ground  that they are capable  of withstanding,  without  appreciable  movement  in the ground  
and with an adequate  factor  of safety,  the forces  imposed  by the loading  on the structure  
under  normal  or broken  conductor  or erection  conditions.  
11.7.2.1  A safe bearing  pressure  of about  200 kPa can be assumed  for checking  resistance  
to downward  or lateral  forces  in the case of ordinary  soil and at the average  foundation  
depths.  
11.7.2.2  The value  could  be three  or four times  this value  in hard rocky  soil and, perhaps,  
one third  of this value  in sandy  or boggy  ground.  
11.7.2.3  In the case of wooden  poles,  foundation  failure  before  pole failure  is desired,  and a 
value  of 345 kPa can be assumed.  
11.7.3 The safe bearing  pressure  of the soil in which  a foundation  or a structure  is to be 
installed,  should  be determined  by site tests.  
11.7.4 For checking  resistance  to upward  forces,  it is commonly  assumed  that the density  of 
ordinary  soil is about  1 600 kg/M3  and the angle  to the vertical  of the sides  of the frustum  
of earth -resisting  uplift  may be taken  as 25° in good  soils to 0° in poor soils.  
11.7.5 In the case of poles,  an increased  bearing  area in the lateral  direction  is often  obtained  
by the addition  of kicking  blocks  at the bottom  and at a point  below  ground/floor  level  that 
is equal  to one-third  of the buried  depth  of the pole,  while  an increased  bearing  area at the 
bottom  is obtained  by the addition  of base plates.  
11.8 Insulators and Fittings  
11.8.1  Mechanical strength requirements  
11.8.1.1  The mechanical  strength  of insulators  and fittings  used in strain  structures  should  
be such that they are at least as strong  as the minimum  breaking  strength  of the phase  or 
earth  conductor  to which  they are attached.  
11.8.1.2  The strength  of suspension  assemblies  should  be such that a factor  of safety  of at 
least 1,5 is provided  under  the loading  imposed  under  broken  conductor  conditions.  
11.8.2  Electrical insulation levels and footing resistance requirements  
11.8.2.1  The basic  insulation  level  required  for a power  line of a given  voltage  depends  on 
many  factors,  such as the anticipated  magnitude  of voltages  caused  by switching  surges  or 
faults,  the altitude  of the line, the possibility  of contamination  of insulators  and the desired  
degree  of immunity  from  lightning.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.8.2.2  
Minimu
m 
insulation  
levels  are 
given  in 
the 
following  
table,  
Table  6, 
but it System 
nomina
l 
RMS  
voltage 
kV System  
fault 
leve
l kA Rated 
peak 
lightning 
impulse  
withstan
d voltage 
kV Rated 
peak 
switching 
impulse  
withstan
d voltage  
(phase -to-
earth  
voltage) kV  Phase -
to-
phase 
voltag
e 
ratio to  
the 
phase -
to-
earth 
voltag
e peak 
value  Rated 
peak 
switching 
impulse  
withstan
d voltage  
(phase -to-
phase  
voltage) kV  60 s RMS 
power  
frequency 
peak 
switching  
withstan
d 
voltage  
(phase  to-
earth 
voltage) 
kV 
12 11 - 75 - - - 28  
24 22 - 125 - - - 50  
36 33 - 170 - - - 70  
48 44 20 250 - - - 95  
72 66 20 350 - - - 140  
100 88 25 380 - - - 150  
145 132 40 550 - - - 230 
245 220 40 850 - - - 360 
300 275 50 1050 850 1.5 1300 - 
362 330 50 1300 950 1.5 1425 - 
420 400 50 1425 1050 1.5 1550 - 
800 765 50 2100 1550 1.5 2400 - 
NOTE : The designed  line insulation  levels  will determine  line equipment  clearances.  The minimum  safety  phase -to-earth  
clearances  shown  in column  3 of Table  3 should  not be interpreted  as specifying  line equipment  clearances.   
In the range  of rated  voltage  that is within  the scope  of this standard,  there  are three  ranges  
with distinctive  insulation  criteria  and therefore  insulation  levels.  They  are given  in 
subparagraphs  (a), (b) and (c) below:  
(a) Range A, for line voltages less than 44 kV:  The main  criterion  is only the lightning  
impulse  over voltages,  which  can be severe  when  the load is disconnected  on the low 
voltage  winding  of a transformer  connected  to a transmission  line. This impulse  voltage  
is usually  reduced  by the use of surge  arresters.  
(b) Range B, for 44 kV to 220 kV lines:  The main  criteria  are the rated  lightning  impulse  
voltage  and the rated  60s power  frequency  voltage,  which  cover  all internal  over-voltages.  
The assumed  footing  resistances  are - 
(i) 132 kV: 20 Ω and  
(ii) 220 kV: 30 Ω. PRD/ SZNS  077: 202 3 
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All rights reserved  (c) Range C, for 275 kV to 400 kV lines:  The main  criterion  is the switching  overvoltage  
(representing  internal  overvoltage),  including  the rated  lightning  impulse  overvoltage,  
based  on footing  resistances  of - 
(i) 275 kV: 30 Ω; and 
(ii) 400 kV: 40 Ω. 
11.8.3  Insulation levels in polluted areas  
 The criteria  for insulation  coordination  in conditions  of pollution  are based  on SANS  IEC 
60815  and on the corresponding  proposed  creepage  distances  given  in the following  table,  
Table 7 . 
Table 7:  Creepage distance over external insulation  
Highest 
system  
RMS 
voltage kV  System 
nominal 
RMS voltage 
kV Creepage distance over external insulation for line, in 
accordance with SA NS IEC 60815  
Lightly 
polluted 
areas  Medium  
polluted 
areas  Heavily 
polluted 
areas  Very heavily 
polluted 
areas  
1211 192 240 300 372  
2422 384 480 600 744  
3633 576 720 900 1116  
4844 770 960 1200 1500  
7266 1150 1400 1800 2200  
10088  1600 2000 2500 3100  
145132  2320 2900 3600 4500  
Highest 
system  
RMS 
voltage kV  System 
nominal RMS 
voltage kV  Creepage distance over external insulation for line, in 
accordance with SA NS IEC 60815  
Lightly 
polluted 
areas  Medium  
polluted 
areas  Heavily 
polluted 
areas  Very heavily 
polluted 
areas  
245220  3920 4900 6100 7600  
300275  4800 6000 7500 9000  
362330  5800 7200 9000 11000   
420400  6700 8400 10500  13000   
800765  12800  16000  20000  25000   PRD/ SZNS  077: 202 3 
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All rights reserved  11.9 Stay Wires  
11.9.1  Installation of stays  
11.9.1.1  A stay should  be attached  to the structure  at the point  of application  of the load 
which  it is designed  to counteract  and should  be installed  in a direction  opposite  to that of 
such load.   
11.9.1.2  The location  should  be such that the clearance  from  the stay wire to any live part of 
the line under  all design  conditions  is not less than the appropriate  phase -to-earth  clearance  
given  in Table  3. 
11.9.1.3.1  Stay wires  should  not pass under,  over or near communication  lines  or the 
associated  poles.  
11.9.1.3.2  Where  this is unavoidable,  stays  should  be installed  in such a way that workers  
working  on the poles  or wires  of the communication  line cannot  come  closer  than the 
appropriate  phase -to-earth  clearance  to any portion  of the stay that could  become  alive  under  
fault conditions.  
11.9.1.4.1  A stay insulator  or an insulated  rod shall  be installed  in every stay.  
11.9.1.4.2  The stay insulator  or insulated  rod shall  be installed  such that in the advent  of the 
stay touching  any live part of a line installed  below  the attachment  point  of the stay that the 
lower  portion  of the stay will not be made  alive.  The angle between the stay wire and the 
pole must be 45 degrees and it shall correspond to the angle between the stay rod and the 
ground.  
In cases where a stay has to be erected, the stay -bulk/plate must be buried in a stay hole 
whose depth is given in Ta ble 4:  Stay holes depth  
Table 4: Stay holes depth  
Stay rod length  Stay hole   Depth (m)  
1.5   1.05  1.30 
2.0        1.45        1.75 
2.4   1.95  2.15 
At the bottom of the stay hole, the hole must be dug in such a way that the stay bulk/plate 
will be placed/lean against the undisturbed ground.  The stay rod slot on the side of the stay 
hole must be 80 mm wide.  
11.9.2  Factor of safety  
11.9.2.1  The strength  of any stay wire used,  should  be such that its ultimate  tensile  strength  
is at least 2,5 times  the maximum  tension  calculated  as indicated  in paragraph  11.5.4 above  
for normal  conditions.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.9.2.2  If stay wires  are used to withstand  loading  due to a broken  conductor  or to erection  
conditions,  the factor  of safety  may be reduced,  but the ultimate  strength  should  be at least 
1,5 times  the maximum  tensile  force  for the appropriate  condition.  
11.9.2.3.1  Higher  factors  of safety  should  be used for stay rods than for stay wires,  especially  
where  threaded  portions  are in tension.  
11.9.2.3.2  A factor  of safety  of 2,5 should  be used for stay rods and one of at least 3 for their 
threaded  portions.  
11.10  Earthing  
11.10.1  Support structures for power lines  
11.10.1.1  All metal  power  line structures  and any metal  work  on wooden  or concrete  
structures,  which  could  inadvertently  become  alive  and which  are within  2.4 m of the ground,  
shall  be earthed.   
11.10.1.2.1  The effectiveness  of the earthing  of a structure  shall  be determined  by measuring  
its resistance  to earth.  
11.10.1.2.2  If this resistance  is so high that the structure  is not earthed,  a supplementary  
earthing  system  should  be provided  in accordance  with /with  due recognition  to SANS  
10199.  
11.10.1.3  A footing  resistance  of less than 10 ohms  is recommended  for terminal  structures  
at stations  and a footing  resistance  of less than 10 ohms  is recommended  for the second,  third  
and fourth  structures  from  a station.  
11.10.1.4  Where  it is not practicable  to provide  a sufficiently  low earth  resistance  to ensure  
that there  will be no danger  to life in the event  of a fault in a structure,  the risk can be reduced  
by the use of fast and reliable  protection.  
11.10.2  Earth wires  
11.10.2.1 To reduce  the number  of outages  caused  by lightning,  earth  wires  should  be located  
above  the phase  conductors  in such a position  that the cover  angle  is reasonably  small.  
11.10.2.2 Cover  angles  in the range  30° to 45° are recommended  for single  earth  wire 
systems.  
11.10.2.3 Cover  angles  of 30° or less for the outer  conductors  and a 60° cover  angle  to the 
conductors  between  the earth  wires  is recommended  for two earth  wires.  
11.10.2.4 Where  earth  wires  are only used to provide  a return  path for earth  fault currents,  
they should  preferably  be located  below  the line conductors  so that if a conductor  breaks,  
there  is a possibility  that it will make  contact  with the earth  wire.  PRD/ SZNS  077: 202 3 
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All rights reserved  11.10.2.5 Earth  wires  installed  as lightning  protection  should  be connected  to earth  at each 
power  line support,  either  through  the support  in the case of metal  supports,  or by an earthing  
conductor  in the case of supports  of non-conducting  materials.  
11.10.2.6 Lightning  protection  on wooden  poles  of lines  operating  at voltages  below  33 kV, 
can be improved  by omitting  earth  wires  and leaving  the insulator  assemblies  unearthed,  
keeping  the insulation  level  as high as possible.  
11.10.2.7 Earth  wire insulators  fitted  with a spark  gap set to 6 mm shall  be installed  in the 
following  circumstances:  
11.10.2.7.1 At terminal  structures  not connected  to the main  station  earth  mat; 
11.10.2.7.2 attraction  station  terminal  structures;  
11.10.2.7.3 on the second,  third,  fourth  and fifth structures  from  the station  if any or all of 
these  structures  have  footing  resistances  of less than 10 Ω; and 
11.10.2.7.4 at all structures  within  800 m of electrified  railway  tracks  or metal  pipelines  
where  the power  line either  crosses,  or runs parallel  to, the railway  or pipeline.  
 
List of IEC standards adopted:  
1. IEC 60364 -4-42:2010/AMD1:2014 – Low voltage electrical installations – part 4 -42: Protection 
for safety – Protection against thermal effects . 
2. IEC 60364 -4-43:2008 – Low voltage electrical installations -part 4 -43: Protection for safety – 
Protection against overcurrent . 
3. IEC 60364 -4-44:2007/AMD1:2015/AMD2:2018 – Low voltage electrical installations – part 4 -
44: Protection for safety – Protection against voltage distur bances and electromagnetic 
disturbances . 
4. IEC 60364 -5-51:2005 – Electrical installations of buildings – part 5 -51: Selection and erection 
of electrical equipment – Common rules  
5. IEC 60364 -5-52:2009 – Low voltage electrical installations – part 5 -52: Selection and erection of 
electrical equipment – Wiring systems.  
6. IEC 60364 -5-53:2019/AMD1:2020 - low voltage electrical installations – part 5 -53: Selection 
and erection of electrical equipment – Devices for protection for safety, isolation, switching, 
control and monitoring.  
7. IEC 60364 -5-54:2011/AMD1:2021 – Low voltage electrical installations – part 5 -54: Selection 
and erection of equipment – Earthing arrangements and protective conductors.  
8. IEC 60364 -5-56:2018 – Low voltage electrical installations – part 5-56: Selection and erection 
of electrical equipment – Safety services.  
9. IEC 60364 -6: 2016 – Low voltage electrical installations – part 6: Verification  
10. IEC 60364 -7-701:2019 – Low voltage electrical installations – part 7 -701: Requirements for 
special installations or locations – Locations containing a bath or shower  
11. IEC 60364 -7-702:2010 – Low voltage electrical installations – part 7 -702: Requirements for 
special installations or locations – Swimming pools and fountains.  PRD/ SZNS  077: 202 3 
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All rights reserved  12. IEC 60364 -7-703:2004 – Electric al installations of buildings – part 7 -703: Requirements for 
special installations or locations – Rooms and cabins containing sauna heaters.  
13. IEC 60364 -7-704:2017 – Low voltage electrical installations – part 7 -704: Requirements for 
special installations or  locations – Construction and demolition site installations  
14. IEC 60364 -7-705:2006 – Low voltage electrical installations – part 7 -705: Requirements for 
special installations or locations – Agricultural and horticultural premises.  
15. IEC 60364 -7-706:2005/AMD1:2 019 – Low voltage electrical installations – part 7 -706: 
Requirements for special installations or locations – Conducting locations with restricted 
movement.  
16. IEC 60364 -7-708:2017 – low voltage electrical installations – part 7 -708: Requirements for 
special  installations or locations – Caravan parks, camping parks and similar locations.  
17. IEC 60364 -7-709:2007/AMD1:2012 – low voltage electrical installations – part 7 -709: 
Requirements for special installations or locations – Marinas and similar locations.  
18. IEC 6 0364 -7-710:2021 – Low voltage electrical installations – part 7 -710: Requirements for 
special installations or locations – Medical locations.  
19. IEC 60364 -7-711:2018 – Low voltage electrical installations – part 7 -711: Requirements for 
special installations o r location – Exhibitions, shows and stands.  
20. IEC 60364 -7-713:2013 – Low voltage electrical installations – part 7 -713: Requirements for 
special installations or locations – Furniture.  
21. IEC 60364 -7-714:2011 – Low voltage electrical installations – part 7 -714: Requirements for 
special installations or locations – External lighting installations.  
22. IEC 60364 -7-715:2011 – Low voltage electrical installations – part 7 -715: Requirements for 
special installations or locations – Extra -low-voltage lighting installations.  
23. IEC 60364 -7-717:2009 – Low voltage electrical installations – part 7 -717: Requirements for 
special installations or locations – Mobile or transportable units.  
24. IEC 60364 -7-718:2011 – Low voltage electrical installations – part 7 -718: Requirements for 
special installation or locations – Communal facilities and workshop.  
25. IEC 60364 -7-721:2017 – Low voltage electrical installations – part 7 -721: Requirements for 
special installations or locations – Electrical installations in caravans and motor caravans.  
26. IEC 60364 -7-729:2007 – Low voltage electrical installations – part 7 -729: Requirements for 
special installations or locations – Operating or maintenance gangways.  
27. IEC 60364 -7-740:2000 – Electrical installations of buildings or locations – Temporary electrical 
installations for structures, amusement devices and booths at fairgrounds, amusement parks and 
circuses.  
28. IEC 60364 -7-753:2014 – Low voltage electrical installations – part 7 -753: Requirements for 
special installations or locations – Heating cables and embedded heating systems.  
29. IEC 60364 -8-1:2019 – Low voltage electrical installations – part 8 -1: Functional aspects – 
Energy efficiency.  
30. IEC 60445:2021 – Basic and safety principles for man -machine interface, marking and 
identification – Identification of equipment terminals, conductor terminations and conductors.  
31. IEC 60479 -1:2018 – Effects of current on human beings and livestock – part 1: General aspects.  
32. IEC 60479 -2:2019 – Effects of current on human beings and livestock – part 2: Speci al aspects.  
33. IEC 60644:2009/AMD1:2019 – Specifications for high -voltage fuse -links for motor circuit 
applications.  
34. IEC 60715:2017 – Dimensions of low -voltage switchgear and controlgear – Standardized 
mounting on rails for mechanical support or switchgear, c ontrolgear and accessories.  
35. IEC 60724:2000/AMD1:2008 – Short -circuit temperature limits of electric cables with rated 
voltages of 1kv and 3 kv.  
36. IEC 60755:2017 – General safety requirements for residual current operated protective devices.  PRD/ SZNS  077: 202 3 
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All rights reserved  37. IEC 61140:2016 – Protection against electric shock – Common aspects for installations and 
equipment.  
38. IEC/TS 61201:2007 – Technical Specifications – Use of conventional touch voltage limits – 
Application guide.  
39. IEC 61557 -1:2019 – Electrical safety in low voltage distributio n systems up to 1 000 V a.c and 
1 500 V d.c – Equipment for testing, measuring or monitoring of protective measures -part 1: 
General requirements.  
40. IEC 61557 -8:2014 – Electrical safety in low voltage distribution systems up to 1 000V a.c and 1 
500V d.c – Equipment for testing, measuring or monitoring of protective measures – part 8: 
Insulation monitoring devices for IT systems.  
41. IEC 61557 -9:2014 – Electrical safety in low voltage distribution systems up to 1 000V a.c and 1 
500 V d.c – Equipment for testing, m easuring or monitoring of protective measures – part 9: 
Equipment for insulation fault location in IT systems.  
42. IEC 61557 -12:2018/AMD1:2021 – Electrical safety in low voltage distribution systems up to 1 
000V a.c and 1 500V d.c – Equipment for testing, meas uring or monitoring of protective measures 
– part 12: Power metering and monitoring devices (PMD).  
43. IEC 61558 -2-6:2021 – Safety of transformers, reactors, power supply units and combinations 
thereof – part 2 -6: Particular requirements and tests for safety i solating transformers and power 
supply units incorporating safety isolating transformers for general applications.  
44. IEC 61921:2017 – Power capacitors – Low voltage power factor correction banks.  
45. IEC 61936 -1:2021 – Power installations exceeding 1 kv  a.c and 1.5 kv d.c – part 1: AC  
46. IEC 62305 -1:2010 – Protection against lightning – part 1: General principles.  
47. IEC 62305 -2:2010 – Protection against lightning – part 2: Risk management.  
48. IEC 62305 -3:2010 – Protection against lightning – part 3: Physical dam age to structures and life 
hazard.  
49. IEC 62305 -4:2010 – Protection against lightning – part 4: Electrical and electronic systems 
within structures.  
50. IEC/TR 62655:2013 – Technical report – Tutorial and application guide for high -voltage fuses.  
51. IEC 60364 -5-55:2011/AMD1:2012/AMD2:2016  – Electrical installations of buildings – part 5 -
55: Selection and erection of electrical equipment – other equipment.  
52. IEC 60364 -4-41:2005/AMD1:2017  – Low voltage electrical installations – part 4 -41: Protection 
for safe ty – Protection against electric shock.  
 PRD / SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Annex 1: Operating Instruction Form  
 
Area: …………………………….. Date: ………………………………… Day: ………………..  
Purpose of Switching  
……………………………………………………………..  
……………………………………………………………  
……………………………………………………………  
 
Completed before switching takes places  Completed as Switching takes place  
Item Switch Number  Open  Close  Rack 
down  Lock  Time  Operators Name  
        
        
        
        
        
        
  
Switching Programme by: ………………………………….. Signature: …………………………….  
Switching programme checked by: …………………………. Signature: …………………………….  
Switching Programme approved (System Controller): ……………… Signature: ……………………  
              
     
 
 
 
              
      
 
 
 
 
 
 
 
 
 
 
     PRD/ SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Annex 2: Operating Authority  
Certificate of Authorization      S/N: …………………………  
Area of Authority: All  
Name of Authorized: ……………………… Employee No : ……………………….. Design ation : 
…………………….  
In terms of the operating regulations for high voltage systems you are hereby authorized to perform duties as 
defined below.  
Authorized person restricted to systems according to definition of Operational Safety Rules  
 
Autho rized to issue, receive, clear/cancel safety documents (Work Permits, Workers declaration, sanction for 
test and limitation of access)  
Authorized to operate on 11 KV swi tches on main lines and spur lines.  
To perform Switching/Linking/Safety testing/Earthing on 11KV, 66 KV, 132 KV switches.  
Safety testing – High Voltage testing up to 132 KV  
Making apparatus safe to work on  
Testing of equipment under normal and abnormal conditions  
Take hand -over, safety testing and application of working earths and additional earths on apparatus to be 
worked on.  
Restoration of supply up to 132 KV.  
Authorized to access and work in prohibited / restricted areas and live chambers.  
Authorized  to carryout switching operation on the following system voltages: 400 KV, 132 KV, 66KV, 11KV  
 
Authorization date: ……………………….  
This Authority supersedes all previous Authorities  
Recommended by: …………………………..  
Assessor : System Control Engineer  
Authorized: ………… ……… Date: ……………………….  
Head of Engineering  
Authorization Expiry date: …………………….. (Three years)  
THE AUTHORIZATION DETAILED ABOVE IS UNDERSTOOD BY ME AND I ACCEPT THE DUTIES 
AND RESPONSIBILITIES SET OUT THEREIN  
Signature: …………………. Date: …………./……………/…………….  
Print Name: ……………………………..  PRD / SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Annex 3: Work Permit Form  
HIRA No: …………  Job No: …………………….  
This permit must be issued or handed to the Person in charge of the work and kept by him/her until the work is 
complete or stopped. The equipment must not again be energiz ed until the permit is cancelled by the Authorized 
person.  
(1) This permit  is issued to or held by ……………………………………..  
Employee No : ………………………… Date: ……………….. Time: ……………………  
(2) Other permit No’s ……………… Have been issued to …………………………………  
Employee No : ………………………………. Must  also be cancelled before the equipment can be energized.  
I Certify that the following plant has been made dead and prepared in accordance with the regulations for the 
work to be carried out on it detailed below. I also certify that it is safe for work to be carried out.  
(3) Plant or section of system on which work is to be carried out: ………………………………….  
……………………………………………………….  
(4) Particulars of work: ……………………………..  
…………………………………….  
……………………………………  
(5) Methods of making safe:  
5.1 ………………………………………….. by ……………………………….. Locked */Withdrawn * 
5.2 ………………………………………….. by ……………………………….. Locked */Withdrawn * 
5.3 ………………………………………….. by ……………………………….. Locked */Withdrawn * 
5.4 ………………………………………….. by ……………………………….. Locked */Withdrawn * 
5.5 ………………………………………….. by ……………………………….. Locked */Withdrawn * 
Desc ribe how earthed ……………………… by ………………………………...  
……………………………………………… by ………………………………...  
……………………………………………… by ………………………………...  
(6) Diagram check by Authorized person that all possible in feeds to equipment being worked on are isolated.  
(Signature): ………………………………….  
(7) Method of proving if isolated circuit is dead (instrument used) ………………………………..  
Proved to (Signature): ………………………………..  
(8) Caution Notices Posed At : ………………………………………………..  
(9) Full name and Signature of Authorized Person issuing Permit: ……………….. Employee No : …………….  
 
(10) PERMIT RECEIVED and understood  
 
(N.B) This permit is not valid unless all relevant portions is completed  
Signed/Communicated: …………………………….. Date: …………………….. Time: ………………….  
 
 PRD/ SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Cancellation or closing of permit to work  
(11) I certify that the work detailed above h as been completed */stopped * and that all personnel are clear.  
11.1 Signature of responsible person in charge of works  
Signed */communicated *: ……………………. Date: ………………….. Time: ……………………  
11.2 Radio */Tele * Information that work detailed above has been completed */stopped * and that all 
personnel are clear received by …………………….. Employee No : ………………………………………  
From: …………………… Employee No : …………………………. Date: ………………………… Time: 
………………..  
11.3 Permit No: …………….. in (1) Cancelled or closed by: …………………… Employee No : …………..  
11.4 Permit No’s: ……………. In (2) cancelled or closed by: ………………….. Employee No : …………...  
11.5 Permit given up by Responsible person in charge of the works and cancelled or closed.  
Full name and signature of Authorized Person …….. Employee No :…………. Date: ………… 
Time:……………...  
Notes: (a) * Cancel inappropriate section  
       (b) Complete in full and return this document to the Control Centre  
 
WORKMAN’S DECLARATION  
I hereby declare that the work to be carried out under the permit has been fully explained to me by th e 
undersigned responsible person and I thoroughly understand the nature and danger of such work  
 
WORKMEN’S NAMES 
AND SIGNATURES  Signing 
On WORKMEN’S NAMES  Signing Off  
    
    
    
    
    
    
    
 
DATE: ………………………….. Time: ……………………………………..  
Signature  of Permit Holder: ………………………….. Full name: …………………………………….  
 
 PRD / SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   LIMITATION OF ACCESS  
HIRA No: ……………………  Job No: ………………………………  
This Copy of limitation of Access form must be filled by person in charge of the work. This shall be in force 
till the work is complet ed or stopped.  
1) Copy held by: …………………………………………………….. Employee No : ……………………  
Designation: ……………………………………… Authority area: ……………………….  
2) Limitation of access issued No: …………………. By: ………………………………  
Employee No : …………….. Date: …………………… Time: ………………… Authority area: …… …. 
3) Receipt : I accept responsibility for the work described on this Limitation of Access and for taking the 
precautions necessary to prevent danger.  
Signature of Authorized Person: …………………………………  
4) Brief description of work to be carried out:  
…………………………………………………………………………  
…………………………………………………………………………..  
5) Location: …………………………………………  
6) Access to: ………………………………………………….  
7) Safety precautions applicable  
(a) Plant and Apparatus  
………………………………………  
………………………………………….  
(b) Environment  
………………………………………………  
…………………………………………………  
(c) Access/General  
………………………………………..  
………………………………………………  
8) Cancellation of copy of limitation of access  
8.1 I certify that the work detailed above has been completed*/stopped* and that all personnel are clear.  
8.2 This limitation of Access No: ………….. has been can celled or closed by ……………………  
……………………………………….. Employee No : …………………………………………..  
8.3 Person in charge of works (Full name and Signature): ……………………………….  
…………………. Employee No : ……………………… Date: ……………………… Time: ………….  
Note: (a) * Cancel inappropriate section  
      (b) Complete in full and return this copy book to Control Centre  
  PRD/ SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Annex 4: Live Work Declaration Form  
SANCTION FOR TEST ON ELECTRICITY PLANT  
HIRA No: …………………………….  Job No: ……………………..  
This sanction for test must be handed or issued to person in charge of the test and kept by him/her until the test 
is completed or stopped. The equipment or system must not be energized until the sanction for test is cancelled 
or closed by the Holder with the Authorized Person.  
(1) This sanction for test is issued to or held by: ……………………………………  
Employee No : ……………….. Date: …………………….. Time; ……………………..  
(2) I certify that the following Apparatus has been made safe in accordance with the Operational Safety Rules 
for testing described on this sanction -for-test to proceed. Signed*/Communicate d*: ………………………  
(3) Planted or section of system to be tested: ………………………………  
………………………………………………………….  
(4) Brief description of testing to be carried out: ……………..  
……………………………………………..  
………………………………………..  
(5) The points of isolation are:  
5.1 …………………………. By …………………………… Locked* /Withdrawn*  
5.2 …………………………. By …………………………… locked*/Withdrawn*  
5.3 …………………………. By …………………………… locked*/withdrawn*  
5.4 …………………………. By ……………………………. Locked*/withdrawn*  
 
(6) Describe earths application: ………………………. By ……………………………..  
………………………………………………………………..  
(7) Full name and signature of Authorized Person issuing Sanction for test: ………  
……………………………………………………………… Employee No : …………………..  
 
(8) Sanction for test received and understood  
(NB) This sanction for test is not valid unless all relevant portions are completed  
Signed*/communicated* ………………………. Date: ………………….. Time: …………………………..  
 
Cancellation or Closing of sanction for test  
(9) I certify that the test detailed above has been completed*/stopped*.  
9.1 Signature of person in charge of work  
Signed*/communicated* …………………………….. Date: ………………………… Time: ………….  
9.2 Radio*/Tele* information that test detailed above has been completed*/stopped*/received*  
By: ……………………………. Employee No : ……………………..  
From: …………………………………. Employee No : …………… Date: ………………… Time: 
……………  
(10) Sanction for  test given up by responsible person in charge of the tests and cancelled or closed.  
Full name & Signature of Authorized person; …………………………………..  
Employee No : ………………….. Date: ……………………. Time: …………………………….  
Notes: (a) *Cancel inappropriate section  
        (b) Complete in full and return this sanction for test to the control centre.  PRD / SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   CLEARANCE  
I, the responsible  person,  hereby  notify  the undersigned  appointed  operator  that the work  detailed  in the above  
work  permit  has been  completed,  all workers  have  been  withdrawn  from  the chambers  or apparatus,  and the 
apparatus  is ready  to be returned  to service  in accordance  with the Safety  Standards.  
Special  comment  on work  performed:  ..................................................................................... ..............  
............................................................................................................................. ..................................  
Responsible  person  ...............................................  Appointed  operator  ....................................  
Date  ......................................................................  Time  Required  ...........................................   PRD/ SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Annex 6: Control Panel Label/Tag  
Control Panel Label/Tag  No. ..................  
Station  ...........................................................................................  
Control Panel  ..........................................................................  
Permit No . ..................................... ..................................  
Earthing Devices in Use  (if any)  
No. Type  Position  Time  Date  
     
     
     
     
     
     
     
     
 
Appointed  operator  ..........................................................  
Date  ..................................................................................  
 
 
 
 
 
 PRD / SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved   Anne x 7: Access Keys Register  
 
Name  Surname  Employee  
Number  Key #  Date 
Received  Date 
Returned  Signature  
       
       
       
       
       
 
 
  
 
PRD/ SZNS  077: 202 3 
Edition 1  
© Eswatini Standards Authority 202 3   
All rights reserved     
Bibliography 
© Eswatini Standards Authority 202 3   
All rights reserved