PUBLIC REVIEW DRAFT, OCTOBER 2008KENYA STANDARD KS 1882-1:2008 
ICS 33.180.01 
© KEBS 2008 First Edition 2008  
 
 
  
 
  
 
Code of practice — Installation of 
telecommunication cables —  
 
Part 1: Fibre optic cable in buildings 
 
 
 
  
 
  
 
 
 
PUBLIC REVIEW DRAFT, OCTOBER 2008 
 
 
 
 
 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
ii © KEBS 2008 — All rights reserved TECHNICAL COMMITTEE REPRESENTATION 
 
The following organizations were r epresented on the Technical Committee: 
 
Widestream Communications Limited Kenya Broadcasting Corporation 
Meteorological Department 
Kenya Power & Lighting Company  
Telea (K) Limited 
SR Kenya Limited 
Department of Defence 
Kenya Police Force 
Communications Commission of Kenya Kenya Bureau of Standards — Secretariat 
 
  
 
   
REVISION OF KENYA STANDARDS 
 
In order to keep abreast of progress in industry, Ke nya standards shall be regularly reviewed. Suggestions 
for improvement to published standards, addressed to  the Managing Director, Kenya Bureau of Standards, 
are welcome. 
 
  
 
   
 
  
© Kenya Bureau of Standards, 2008 
 
Copyright. Users are reminded that by virtue of Section 25 of the C opyright Act, Cap. 12 of 2001  of  the Laws of Kenya, copyrig ht 
subsists in all Kenya Standards and except as provided under Section 26 of this Act,  no Kenya Standard produced by Kenya Bureau  of 
Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in w riting 
from the Managing Director. 
 
   
 
  
 
   
 
  
 
 
 
 
  
 PUBLIC REVIEW DRAFT, OCTOBER 2008KENYA STANDARD KS 1882-1:2008 
ICS 33.180.01 
© KEBS 2008 — All rights reserved  iii  
 
 
  
 
 
 
Code of practice — Installation of telecommunication cables —  
 
Part 1: Fibre optic cable in buildings  
 
            
   
 
KENYA BUREAU OF STANDARDS (KEBS) 
 
Head  Office:  P.O. Box 54974, Nairobi-00200, Tel.: (+254  020) 605490, 69028000, 602350, Mobile: 0722202137/8, 0734600471/2; 
Fax: (+254 020)  604031 
E-Mail: info@kebs.org,  Web:http://www.kebs.org  
 
KEBS Coast Region 
P.O. Box 99376, Mombasa 80100 
Tel: (+254 041) 229563, 230939/40 
Fax: (+254 041) 229448 E-mail: kebs-msa@swiftmombasa.com KEBS Lake Region 
P.O. Box 2949, Kisumu 40100 
Tel: (+254 057) 23549,22396 
Fax: (+254 057) 21814 
E-mail: kebs-ksm@swiftkisumu.com KEBS North Rift Region 
P.O. Box 2138, Nakuru 20100 
Tel: (+254 051) 210553, 210555PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
iv © KEBS 2008 — All rights reserved FOREWORD 
 
This Kenya standard wa s prepared by the Communication Equipment  under the mandate of the Electrical 
Industry Standards Committee in accordance with the procedures of the Bureau and is in compliance with 
Annex 3 of the WTO/TB Agreement. 
 
This Kenya Standard specifies installation practices for fibre optic cables in commercial premises, including 
single or multiple buildings in a campus environment. 
 
The guidelines provided in this standard are intended as  a reference both for installers of high performance 
communications cables and for their customers, and are aimed at achieving proper installation of such 
cabling systems. Failure to comply with the insta llation practices described in this Kenya Standard might 
severely degrade the performance of the cabling. 
 
Normative and informative annexes  
 
A 'normative' annex is an integral part of a standard, whereas an 'inf ormative' annex is only for information 
and guidance. 
 
 
  
 
Summary of development  
 
This Kenya Standard, 
having been prepared 
by the Communication Equipment Technical 
Committee was first 
approved by the 
National Standards 
Council in December 2008  
 Amendments issued since publication 
Amd. No. Date Text affected 
   
   
   
   
   
 PUBLIC REVIEW DRAFT, OCTOBER 2008PD/09/01/2005 
© KEBS 2006 — All rights reserved  v  
1 Scope ....................................................................................................................... ......................... 1 
2 Normative re ferences ........................................................................................................ ................ 1 
3 Definitions an d abbreviations ............................................................................................... ............. 1 
3.1 Defini tions ............................................................................................................... ........................... 1 
3.2 Abbrev iations ............................................................................................................. ........................ 4 
4 Planning ............................................................................................................................... .............. 4 
5 Trunking and conduits ....................................................................................................... ................ 6 
5.1 Trunking ............................................................................................................................... .............. 6 
5.2 Con duits .................................................................................................................. .......................... 6 
6 Prepara tion ................................................................................................................. ....................... 6 
7 Installa tion ................................................................................................................ ......................... 7 
7.1 General cabling practice .................................................................................................................... 7 
7.2 Temporar y labelling ....................................................................................................... .................... 8 
7.3 Protection of installed cables ............................................................................................................. 8 
7.4 General cons iderations .................................................................................................... ................. 8 
7.5 Underfloor insta llation of cables ......................................................................................... ............... 8 
7.6 Installation of cabl es in wall trunking ................................................................................... .............. 8 
7.7 Installation of cabl es in ceiling voids ................................................................................... .............. 9 
7.8 Vertical cabling (backbone cabling) ....................................................................................... ........... 9 
7.9 Installation of cabl es through firewalls .................................................................................. ............ 9 
Bibliogr aphy .................................................................................................................. ................................... 10 
 
 
 
 PUBLIC REVIEW DRAFT, OCTOBER 2008PUBLIC REVIEW DRAFT, OCTOBER 2008 
KENYA STANDARD KS 1882-1:2008  
© KEBS 2008 — All rights reserved  1   Code of practice — Installation of telecommunication cables — Part 1: 
Fibre optic cable in buildings 
 
 
1 Scope 
 1.1 This part of this Kenya Standard addresses installation requirements, primarily for indoor cabling, but 
also for campus-wide inter-building cabling, for high per formance fibre optic cable that serves to transmit 
voice, video and data telecommunication. 
 
1.2 This Kenya Standard emphasizes optimal link perf ormance through the proper planning, design, 
installation and quality testing of the cables, and st rict adherence to the guidelines given in this Kenya 
Standard to avoid possible compromising of the integrity and performance of the installation. 
 
2 Normative references 
 
The following referenced documents are indispensable for the application of this standard. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
KS ISO IEC 11801, Information technology — Generic cabling for customer premises  
 
3 Definitions and abbreviations 
 For the purposes of this standard, the follo wing definitions and abbreviations apply:  
 
3.1 Definitions 
 
3.1.1 
application 
a system, with its associated tran smission method, that is supported by telecommunication cabling 
 
3.1.2 
backbone cabling the vertical or riser cabling of a multi-storey buildi ng or inter-building cabling on a multi-building site, owned 
by the telecommunication carrier or any other party, which forms the permanent reticulation of that building 
or site and which is generally accessib le for future additions or alterations 
 
3.1.3 
bonding the permanent joining of metallic parts to form an el ectrically conductive path that will assure electrical 
continuity  
3.1.4 
cabinet a container that can enclose conne ction devices, terminations, apparatus, wiring and equipment, including 
active electronic equipment  
 
3.1.5 
cable an assembly of one or more cable units of the same type and category in an overall sheath 
 3.1.6 cable element 
the smallest construction unit (for example a pair, a quad or a single fibre) in a cable PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
2 © KEBS 2008 — All rights reserved  
NOTE The cable element can have a shield. 
 
3.1.7 
cable unit a single assembly of one or more cable elements of the same type or category 
 
NOTE The cable unit can have a shield. 
 
3.1.8 cabling 
physical media for conducting signals 
 
3.1.9 
campus premises that contain one or more buildings 
 3.1.10 channel 
the end-to-end transmission path that connects two pi eces of application-specific equipment, including 
equipment and work area cables 
 
NOTE A channel occurs, for example, between the end of the patch  cord on the patch panel in the equipment room and the end of 
the fly-lead that connects it to  the connection terminal equipment. 
 
3.1.11 
commercial building 
a building, or part thereof, that is intended for office use 
 
3.1.12 
customer a person who contracts with a telecommunication carrier or service provider to supply a telecommunication 
service 
 
3.1.13 
distributor an assembly of components and equipment, for exampl e a patch panel (see 3.1.24) and patch cords (see 
3.1.23), used to connect cables  
3.1.14 
fibre optic cable 
optic cable a cable that comprises one or more fibre optic cable elements 
 3.1.15 floor distributor 
the distributor (see 3.1.13) used to  connect the horizontal cable and other cabling subsystems or equipment 
(see also 3.1.27) 
 
3.1.16 
frame any assembly of cabling hardware that provides for t he termination and the cross-connection of cabling by 
means of jumpers (see 3.1.21) or patch cords (see 3.1.23) 
 
NOTE The international term is distributor. 
 
3.1.17 
generic cabling a structured telecommunication cabling system that is capable of support ing a wide range of applications 
 
NOTE 1 Generic cabling can be installed without prior knowledge of the required applications.  
 
NOTE 2 Application-specific hardware do es not form part of generic cabling. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008 
© KEBS 2006 — All rights reserved  3 3.1.18 
grounding 
earthing a conducting connection, whether intentional or acci dental, between an  electrical circuit or equipment and 
the earth, or to a conducting body that can serve as an earth  
3.1.19 
hardware 
devices used to connect cable (or wires) to facilitate cross-connection or extension to another cable or other 
equipment 
 3.1.20 horizontal cabling 
the cable reticulation that serves a particular floor of  a building, in order words, that extends from (and 
includes) the telecommunication outlet connector at the work area to the horizontal  cross-connection in the 
telecommunication closet (see 3.1.27) 
 
3.1.21 
jumper 
a cable unit or cable element without connectors, used  to make an interconnection or a cross-connection 
 
3.1.22 
link the transmission path between any two interf aces of generic cabling (see 3.1.17) 
 
NOTE The link does not include equi pment and work area cables. 
 
3.1.23 patch cord 
a flexible cable unit or element with one or more conn ectors, used to establish connections on a patch panel 
 
3.1.24 
patch panel a facility that enables the termination of cables or c able units and also their interconnection, or cross-
connection (or both), primarily by means of a pat ch cord (see 3.1.23) or jumper (see 3.1.21) 
 
NOTE This facility is also known as  an optic distribution frame (ODF). 
 
3.1.25 
service provider 
the organization(s) responsible for providing public network services 
 
3.1.26 
sheath the outer protective layer of a cable 
 3.1.27 telecommunication closet 
an enclosed space for housing telecommunication equipment, cable terminations and cross-connection 
cabling 
 
NOTE The telecommunication closet is a recognized cross-connection point between the backbone (see 3.1.2) and the horizontal 
(see 3.1.20) cabling subsystems. 
 
3.1.28 
telecommunication infrastructure the components, namely telecommunication equipment spaces, cable pathways, grounding (see 3.1.18), 
wiring and termination hardware that, together, prov ide the basic support for the distribution of all 
telecommunication information 
 
3.1.29 
telecommunications PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
4 © KEBS 2008 — All rights reserved the branch of technology that is concerned with the transmission, emissi on and reception of signs, signals, 
writing, images and sounds, in other words, informat ion of any nature, by cabl e, radio, optic or other 
electromagnetic systems 
 
3.1.30 
topology the physical or logical configuration of a telecommu nication system, for example, star, bus or ring 
 
3.1.31 
wiring 
the single-pair, two-pair, three-pair or four-pair cable used between a cable terminal and an individual user's 
telecommunication outlet 
 3.1.32 work area 
a building space where the occupants interact with telecommunication equipment  
3.2 Abbreviations 
 
HVAC heating, ventilation and air conditioning 
 
IEC International Electrotechnical Commission 
 
ISO International Organization for Standardization  
PVC polyvinyl chloride 
 
4 Planning 
 
4.1 The proper installation of communication cables ca lls for thorough planning before installation starts. 
Time spent planning the routes before starting installa tion can save many hours of frustrating rerouting and 
recabling. It can also mean the difference between a system that works and one that does not work. 
 
4.2 Issues to consider when planning an installation include 
 
a) establishing the specific requirem ents and services relevant to the customer's proposed installation and 
terminal equipment, 
 
b) establishing the existence of a cable network infrastructure, 
 
c) the accessibility of the cable network system, 
 d) assessing the current and future requi rements for a cabling infrastructure, 
 e) identifying and noting the position of other utility services, including plumbing, electrical cables and 
heating, ventilation and air cond itioning (HVAC) services, and 
 f) identifying the desirability of using flame-proof or flame-retardant cable in the proposed installation. 
 
4.3 It is highly recommended that electrical layout pl ans, or floor layout plans (or both) be obtained 
before the communication cabling infrastructure for a building is designed. The plans will indicate the 
location, type and extent of the cable support infrastr ucture in the form of conduits, inspection boxes and 
cable trays. The plans should also indicate if the support systems are intended for the exclusive use of a 
particular reticulation system, or if they can be used for a variety of services. Support systems that are 
intended for other services shall not be used for the installation of the fibre optic service. 
 
4.4 In the absence of drawings, a physical inspection  of the facilities should be done and the size and 
location of cable support structures  and their accessibility noted. The capa city of the conduits, trunking or 
tray intended to be used shall be visually inspected. The support channel shall not be overfilled. Instead, the 
possibility of removing redundant cables before installing new ones shall be investigated. Should this still not 
have the desired result, a new route shall be installed. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008 
© KEBS 2006 — All rights reserved  5 4.5 Future expansion shall be allowed for when planning fo r, or using, cable support structures. Although 
no strict rules exist as to the capacity fill of a channel, future re quirements and upgrades shall be kept in 
mind. A general rule is that an open channel or cable tray may not be filled to more than 50 % of its total 
capacity upon initial installation. For conduits and pipes  the maximum fill capacity should not exceed 33 %. 
When the open channel reaches 75 % of total capacity fill, a new route should be planned. The planning for 
a new route allows for the future addition of cables  required for the purpose of expansion or for new 
applications.  
4.6 When planning the routes for the support infrastructu re, it shall be borne in mind that the horizontal 
cables are laid out in a star topology, in other words, the cables that terminate at the work area are fed from 
a central point, namely the floor distributor. In larger inst allations, this could take the form of a hierarchical 
star topology, using a building distribut or to feed several floor distributor s, again using a star topology. (See 
KS ISO IEC 11801.) 
 
 
 
Figure 1 — Hierarchical star topology 
 
4.7 Under normal circumstances the maximum distance of  fibre optic cable shall be in accordance with 
KS ISO IEC 11801. 
 4.8 A telecommunication closet (see 3.1.27), norma lly a 480 mm equipment cabinet, shall be used to 
house the termination of the horizontal cable. Po ssible future additions shall also be considered. 
 
4.9 Equipment cabinets can be of either the floor-stand ing or the wall-mounted type. In either case, the 
position of the cabinet shall be permanent. In a clea n, protected environment, an open equipment frame may 
be used instead of a cabinet.  
4.10 The location of any firewalls that might obstruc t the path of the planned route shall be noted. If no 
provision has been made for cable routes through firewa lls, the architect or engineer should be consulted. 
Under no circumstances shall the integr ity of firewalls be violated by dr illing or breaking holes through them 
unless provision has been made for the reinstatement of their integrity. 
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
6 © KEBS 2008 — All rights reserved 4.11 When sealing the spaces around cables or suppo rt structures that penetrate a firewall, only 
approved building materials shall be used.  Many types of expandable foam th at are popular among installers 
for repairing large holes in walls are highly flammable and shall not be used. 
 
5 Trunking and conduits 
 
5.1 Trunking 
 
Before the installation of trunking and conduits, special care should be taken to adhere to cable 
specifications with regard to ben ding radii. It is important to adhere to the 33 % maximum fill ratio for 
conduits and closed trunking and the 50 % maximum fill ratio for open trays. 
 
5.2 Conduits 
 
5.2.1 All exposed cabling should be housed in rigid me tal or PVC conduits and flexible PVC tubing for 
additional protection. The use of PVC products shoul d be avoided where low halogen levels, a zero halogen 
level or fire retardant properties are required. 
 
5.2.2 No single, uninterrupted section of conduit s hould extend for more than 30 m. In addition, no 
segment shall contain more than two 90° bends bet ween the two ends or between any two pull boxes. 
 
5.2.3 The radius of a bend should be at least six times the inside diameter of the conduit for conduits of 
diameter exceeding 50 mm. For conduits of diameter 50 mm or less, the bend radius should be ten times the 
inside diameter of the conduit. 
 
5.2.4 The minimum bend radius to be installed in the conduit should be taken into account and should be 
the larger of the conduit bend radius (see 5. 2.3) and the cable bend radius (see 6.3). 
 
6 Preparation 
 
6.1 Proper performance will only be achieved with care ful installation of the cable and adequate support 
of the installed cable. It is therefore imperative that  the cabling routes be properly planned and supported. 
The preparation of the cable installation includes the pr eparation of the cable routes and the cable support 
structure. 
 6.2 The installer shall establish that the pathways defi ned in the installation specification are accessible 
and available in accordance with the installation programme and that all routes are open and free of any 
obstruction. Ceiling tiles, skirting covers and any access apertures shall be opened up at convenient 
locations and where there is a change in direction of the route. The customer  shall be advised of all 
proposed deviations.  6.3 The installer shall ensure that the routes are open and sufficiently accessible to allow for the cable to 
be pulled without exceeding the maximum pulling limit. T he installer shall ensure that the bend radii of the 
routes are checked to be smooth and gradual. The cabl e shall not be pulled around too many bends or sharp 
corners and the pulling route shall be so planned that the pulls are as straight as possible. Under no 
circumstances shall the cable be allowed to be bent at a radius less than the minimum bend radius. As a rule 
of thumb the minimum bend radius is at least twenty ti mes the diameter of the cabl e in the case of concentric 
fibre optic cables. Ruggedized indoor fibre cables ar e more flexible and could have a smaller bend radius. 
 6.4 The installer shall establish that the environmental  conditions within the pathways and the installation 
methods to be used are suitable for the design of the cable to be installed. Since moisture affects cable 
performance, places that are damp or where liquids c an accumulate should be avoided as far as possible. 
 
6.5 Other environmental factors shall also be consi dered. Cables shall not be installed in areas of 
extreme temperatures. The installer shall ensure that the cable is rated for the expected temperature range 
by confirming the cable specifications with the supplier or the manufacturer. 
 
6.6 Cabling routes should be kept clear of metal ro ofs, steam pipes, ovens and other sources of heat, 
such as the outsides of refrigeration plants. 
 
6.7 All types of cable require some form of suppor t. The cable supports should be spaced not more than 
1,5m apart and cable sag between supports shall not ex ceed 30mm. The cable supports shall have no sharp PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008 
© KEBS 2006 — All rights reserved  7 edges that can damage the cable. The contact area of the support should have a contact surface that is 
larger than the minimum bend radius of the cable. 
 
6.8 When installing cabling above su spended ceilings, the cable should be  supported from the roof or a 
wall. Cables shall not be laid dire ct on top of ceiling tiles or be tied to the ceiling support  wires or metal 
straps.  6.9 The installer shall establish that the existing pathwa ys are capable of supporting the full weight of the 
cables to be installed. If new supports are being insta lled, only materials rated for the application shall be 
used. 
 
6.10 It is essential that pathways are left clean and free fr om obstruction with all separators and bridging 
pieces in place before installation. Access points shall not be obstructed. 
 
6.11 The installer shall establish the proposed storage locations for all cabling components and 
accessories and shall ensure that the environmental conditions in those locations are suitable and that 
appropriate security is available. The installer shall ensure that fibre c ables are pretested to confirm their 
continuity and length. Following testing, the ends of stor ed cables shall be sealed. Any attached certificate or 
test records related to the quality and quantity of the cable contained on the reel shall be retained and 
compared to the pretest results.  6.12 The installer shall determine the proposed locations at which cabl e drums will be positioned during 
the installation programme, establish the accessibility and availability of those locations and ensure that all 
the necessary installation accessor ies and equipment are available. 
 
6.13 The installer shall label the physical positions of  all the points and cabinets with temporary labels 
after consultation with the client and shall update the pl an accordingly. If no plan is available, the installer 
shall make a rough sketch to indicate all the offices a nd the locations of the cabling system terminations, and 
also how the installation shall be numbered. If this is not prescribed by the client, the installer shall plan a 
logical labelling system, label all housings and update the plan accordingly. 
 
6.14 The installer shall plan each cable route and s hall decide how the cables shall be pulled to the 
destination points and from which direction the pulling shall be facilitated. It might be better to pull from the 
cabinet or from some common point along the route to wards the work area. Alternatively, circumstances 
might require the pulling of the cable from the work area towards the cabinet. In some cases it might be 
possible to measure and cut the cables before insta llation and then to pull bundles of cables rather than 
single cables. 
 6.15 It is important that these plans be communicated to all members of the installation team to avoid any 
misunderstandings and resultant loss of materials or productivity (or both).  6.16 Label the cables with the same number on each end using temporary, wrap-around labels that can 
be discarded once the cable has been permanently labe lled and marked. The number on the label shall 
correspond with the numbering on the plan.  
6.17 The installer shall check that all draw wires are in tact and that they can move freely. If no draw wires 
are available, fish tape shall be used to pull the cables. 
 
6.18 Safety measures to be taken include ensuring that  all the necessary guards, protective structures 
and warning signs are available to protect the c abling equipment, cable installers and bystanders. 
 
7 Installation 
 
7.1 General cabling practice 
 
7.1.1  The maximum pulling tensions as detailed in the manufacturer's specification shall not be exceeded 
when drawing in the cables. Cables shall be installed in accordance with the ma nufacturer's specification. 
 7.1.2  Most installation problems can be avoided by avoi ding sharp corners, kinks and turns and gradually 
pulling manageable lengths of cable into place, without undue snatching. 
 
7.1.3  Performance specifications for cable and connec ting hardware are based on the use of proper 
installation practices and cable management techniques  in accordance with the manufacturer's guidelines. If PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
8 © KEBS 2008 — All rights reserved the recommended precautions and installation methods ar e not observed, the transmission capabilities of 
cabling components as specified might not be achieved. 
 
7.2 Temporary labelling 
 
When pulling several runs of cable al ong a route at the same time, the lo ose ends of each cabling run shall 
be labelled with a unique identifier to aid identification of  each cabling run. Cables shall always be labelled 
before installation. This can be done by using tempor ary labels that can be replaced by permanent labels 
during the termination process. 
 
7.3 Protection of installed cables 
 
Restraining clips or ties shall be fi tted, as required, to maintain the minimum bend radii for fixing. Where 
there is a risk of the ingress of fluids or other contam inants, exposed cable ends s hall be fitted with suitable 
protective caps until terminated. After installation, ca re shall be taken to prevent installed cables from 
suffering excessive (steady state) st rain by introducing suitable supports. 
 
7.4 General considerations 
 7.4.1  To prevent damage (excess bending), no more cable should be unspooled at any one time than the 
length required and the cable should be drawn direct from the cable reel to avoid its getting tangled. Cable 
should not be unspooled sideways over the reel flange. If the cable is removed from the cable reel, it should 
be coiled in a figure-of-eight pattern to prevent tangling and longitudinal twists. 
 
7.4.2  When using cut lengths the installer shall ensure that suitable excess length is provided to take into 
account any bends in the pathway. 
 
7.4.3  When pulling cables around tight bends, damage to the outer sheath through pulling stress, friction 
and strain should be avoided. Cable guides or additional  personnel should be used to assist with cable 
pulling at these points.  
7.5 Underfloor installation of cables 
 
7.5.1  When installing cabling runs in underfloor system s (raised or computer flooring), the cable should be 
installed in either an open tray or in closed metal trun king. Ideally, cable routes should follow a path parallel 
to the building's walls. Cable routes shall not be diagonal to the building's walls. 
 
7.5.2  Before drawing in new cable the installer shall ensure  that the draw wire is free to move and is not 
entangled with existing cables.  
7.5.3  The draw wire should be securely fixed to the sheath or strain relief element of the cable in 
accordance with the manufacturer's recommended met hod. Under no circumstances shall the draw wire be 
attached to the fibres of the cable.  
7.5.4  Cables should always be pulled slowly and smooth ly, and the maximum pulling stress of the cable 
shall not be exceeded as this might damage the protecti ve sheath of the cable or the fibres inside the 
sheath.  
7.5.5  When installing cables in trays for horizontal or ve rtical runs, the cables shall be secured with cable 
strap ties at appropriate distances. Care sha ll be taken not to overtighten cable strap ties. 
 
7.6 Installation of cables in wall trunking 
 
7.6.1  Cable routing through visible trunking systems shou ld not only satisfy the functional requirements; 
the overall aesthetic concept of the building or the environment should not be overlooked. 
 7.6.2  All the safety requirements with regard to the se paration of mains electricity cables and fibre optic 
cables shall be satisfied. 
 
7.6.3  The installation process shall not degrade the intended environment al performance, for example, 
appropriate seals shall be fitted and fi re barriers shall comply with t he building requirements. Metallic 
trunking installation systems and accessories shall be included in the protection measures against electric PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008 
© KEBS 2006 — All rights reserved  9 shock hazard through proper grounding and bonding. Live wires shall be not accessible after removing the 
wall trunking cover. 
 
7.6.4  Cables shall be so installed as to allow for the future installation of additional cables without damage 
to either the old or the new cables. 
 
7.7 Installation of cables in ceiling voids 
 
7.7.1  Particular care should be taken when installing cabl es in ceiling voids. Cables shall not be installed 
in ventilation ducts. Cables shall not lie direct  on ceiling tiles or fluorescent light boxes. 
 7.7.2  Proper support shall be provided. If cable trays or  closed metal trunking cannot be used, support 
brackets may be used, but these shall be spaced not more than 1.5 m apart to minimize cable sag. Cable 
sag shall not exceed 30 mm between fasteners. 
 
7.7.3  Conduits may be installed in the ceiling void, but inspection boxes shall be provided at regular 
intervals. 
 
7.7.4  Cables shall not be tied to the ceiling suspension wires. The cable ties used to bundle the cables 
shall not be overtightened; the purp ose of the cable ties is to keep the cables in a neat bundle. 
Overtightening can lead to distortion of the cable's physical parameters and a decline in performance. 
 
7.7.5  High-temperature areas shall be avoided and as mu ch clearance from metal roofs as possible shall 
be maintained. 
 
7.7.6  The installer shall not leave excessive service loops or slack in the ceiling since these are difficult to 
manage and can lead to errors when using optic test equipment to locate the distance to a fault. Care shall 
be taken to leave only enough slack to allow for future maintenance purposes. 
 
7.8 Vertical cabling (backbone cabling) 
 
7.8.1  When installing cabling runs in vertical risers, lowe ring the cable is preferable to pulling it up the rise. 
This practice is referred to as t he top-down method of installation. 
 7.8.2  When using the bottom-up method of installation wh ere cables are pulled up, the cables shall be fed 
carefully through each floor of the building. Particular  care shall be taken to ensure that the cable is not 
overstressed and that the cabl e sheath is not subject to any undue stress es owing to friction at any contact 
points. 
 7.8.3  It is recommended that a strain-relief loop or appropr iate fixings be provided at every second floor to 
avoid excessive gravity force on the cables. Care shoul d be taken that the radius of the strain relief loop 
conform to the manufacturer's specified bend radius.  
7.9 Installation of cables through firewalls 
 
When it is necessary to penetrate a firewall or protecti on structure, the integrity of  this structure shall be 
restored to an acceptable level.  
 PUBLIC REVIEW DRAFT, OCTOBER 2008KS 1882-1:2008  
10 © KEBS 2008 — All rights reserved  
Bibliography 
 
KS 662, Kenya Wiring Regulations  
 
IEC 60794-1-1, Optical fibre cables — Part 1-1: Generic specification — General