Czech Metrology Institute  
Okružní 31, 638 00 Brno  
 
1. ------IND- 2018 0592 CZ - EN- ------ 20181224 --- --- PROJET 
Executive summary for the EC (not part of this legislation)  
‘Electricity meters’  may be placed on the market and put into use in the Czech Republic either pursuant 
to Directive 2014/32/EU (MID) or, in areas outside the MID’s scope, as legally controlled measuring 
instruments pursuant to Act No  505/1990 on metrology, as amended. Pursua nt to the Act, legally 
controlled measuring instruments are instruments that are included in the list of the types of legally 
controlled measuring instruments (Implementing Decree No  345/2002) and, at the same time, intended 
(by the manufacturer/importer) for measurements of relevance to the protection of public interests in 
areas of consumer protection, contractual relations, imposition of sanctions, fees, tariffs and taxes, 
health protection, environmental protection, occupational safety, or the protectio n of other public 
interests protected by special legislation . This means that their purpose is similar to that used for 
defining regally controlled products – measuring instruments and non -automatic weighing instruments 
– under Directives 2014/31/EU and 20 14/32/EU. The requirements of this regulation do not apply to 
measuring instruments placed on the market in the Czech Republic for purposes other than the above 
purposes defined by Act No  505/1990 on metrology.  
The purpose of this notified legislation is t o lay down:  
1) metrological and technical requirements for legally controlled measuring instruments and tests 
for the purposes of type approval, in the case of instruments placed on the market without 
conformity assessment pursuant to the MID, and  
2) tests for t he purposes of verifying legally controlled measuring instruments (after they have 
been placed on the market), regardless of whether they have been placed on the market pursuant 
to Act No  505/1990 on metrology or pursuant to the MID, with conformity assess ment.  
(End of executive summary.)  
 
Contact person:Mgr.Tomáš Hendrych  
Telephone:+420 545 555 414  
 
 
P U B L I C   D E C R E E 
 
As the authority with substantive and territorial jurisdiction in the matter of laying down metrological 
and technical requirements  for legally controlled measuring instruments and laying down the methods 
for type approval and verification of legally controlled measuring instruments under §  14(1) of Act 
No 505/1990 on metrology, as amended (hereinafter the ‘Metrology Act’), and in acc ordance with the 
provisions of §  172 et seq. of Act No  500/2004, the Administrative Procedure Code (hereinafter the 
‘APC’), the Czech Metrology Institute (hereinafter the ‘CMI’) commenced ex officio proceedings on 
15 March  2017 pursuant to §  46 of the APC,  and, based on the supporting documents, issues the 
following:  
 General Measure No  0111 -OOP -C022 -18 
2 I. 
D R A F T   G E N E R A L  M  E A S U R E 
number:0111 -OOP -C022 -18 
laying down metrological and technical requirements for legally controlled measuring 
instruments, including the testing meth ods for type approval and verification of legally 
controlled measuring instruments:  
‘electricity meters’  
 
With a view to the relevant EU legislation and Czech national legislation, electricity meters are a type 
of measuring instrument whose placement on the market and into circulation, in terms of applicability 
of this legislation, is classified into three groups, namely:  
a) class A, B and C active energy meters intended for use in commercial, residential and light 
industrial environments;  
b) active energy mete rs intended for applications other than residential, commercial and light 
industry environments, and the functions that the electricity meters referred to in this paragraph 
and in paragraph (a) possess in addition to measuring active electrical energy, e.g . measurement 
of reactive energy  
c) class 2 induction active energy meters bearing the EEC mark.  
In the case of the electricity meters referred to in (a), the process of placing them on the market and into 
operation, including the metrological requirements an d testing methods for the meters, is covered by 
Government Regulation No  464/2005 and 120/2016 laying down the technical requirements for 
measuring instruments1 (hereinafter ‘Government Regulation’).For these electricity meters, this General 
Measure lays d own only the metrological and technical requirements and testing methods to be applied 
when these measuring instruments are being verified after they have been placed on the market and into 
circulation, i.e. when undergoing subsequent verification accordin g to Chapter  7.Nevertheless, these 
requirements and methods comply with the Government Regulation and the relevant requirements of 
harmonised standards.  
In the case of the electricity meters and electricity meter functions referred to in points (b) and (c)  that 
are not covered by the aforementioned Government Regulation, this regulation lays down the 
metrological and technical requirements and the test methods to be applied when placing them on the 
market, i.e. when the instruments undergo type approval pur suant to Chapter  5 and initial verification 
pursuant to Chapter  6, as well as the metrological and technical requirements and testing methods for 
subsequent verification pursuant to Chapter  7 carried out after they have been put into circulationThese 
activ ities are not covered by European legislation and are governed by Act No  505/1990 on metrology, 
as amended.  
                                                      
1  The above Government Regulations implement the following into Czech legislation: Directive 2004/22/EC of 
the European Parliament and of the Council of 31  March  2004 on measuring instruments and Directive 
2014/32/EU of 26  February  2014, which concerns conformity assessment and the making available on the 
market of measuring instruments.  General Measure No  0111 -OOP -C022 -18 
3 1   Basic definitions  
For the purposes of this General Measure, terms and definitions pursuant to VIM and VIML2 and the 
following must apply:  
1.1 
electricity meter for measuring energy  
an instrument intended to measure electrical energy by integrating power over time  
1.1.1  
active energy meter, watt -hour electricity meter  
an instrument intended to measure active electrical energy by integrating active output over time  
1.1.2  
reactive energy meter, var -hour electricity meter  
an instrument intended to measure reactive electrical energy by integrating reactive output over time   
1.2 
electromechanical electricity meter, induction electricity meter  
an electri city meter in which currents in fixed coils react with currents induced in the conductive moving 
rotor(s), which causes its (their) movement proportional to the energy to be measured  
1.3 
static electricity meter  
an electricity meter in which current and vo ltage act on solid state (electronic) elements to produce an 
output signal proportional to the energy to be measured  
1.4 
direct connected electricity meter  
an electricity meter intended for use by direct connection to electrical grid  
1.5 
transformer operated electricity meter  
an electricity meter intended to be used while connected to the electrical grid via one or more external 
instrument transformers  
1.6 
multi -tariff electricity meter  
an electricity meter equipped with multiple registers, each of wh ich operates during specified intervals 
corresponding to different tariffs  
1.7 
electricity meter class  
designation of the quality of electricity meters that satisfy the technical and metrological requirements 
specified for a given class of electricity mete rs 
                                                      
2  TNI 01 0115 International Vocabulary of Metrology – Basic and General Concepts and Associated Terms 
(VIM) and International Vocabulary of  Legal Metrology (VIML) are part of the technical harmonisation 
compendium ‘Terminology in the field of metrology’, which is publicly available at www.unmz.cz.  General Measure No  0111 -OOP -C022 -18 
4 1.7.1  
accuracy classes of electricity meters – 0.5; 1; 2; 3; 0.2  S; 0.5  S and 1  S 
designation of the quality of electricity meters that satisfy the technical and metrological requirements 
specified by the relevant technical standards and whose type has been approved pursuant to the 
Metrology Act;the number in the class designation represents the electricity meter’s accuracy class  
1.7.2  
class A, B and C electricity meters  
designation of the quality of electricity meters that satisfy the technical and metr ological requirements 
specified by Government Regulation No  464/2005 laying down the technical requirements for 
measuring instruments1 and that have been placed on the market and put into use through the conformity 
assessment process  
1.8 
current, I 
electri cal current flowing through the electricity meter  
1.8.1  
starting current, Ist 
the lowest declared value of current at which the electricity meter registers electrical energy at unity 
power factor (for three -phase electricity meters, with balanced load)  
1.8.2 
minimum current, Imin 
the lowest value of current for which accuracy requirements are specified by this regulation;less strict 
accuracy requirements apply at Imin and between Imin and Itr 
1.8.3  
transitional current, Itr 
the value of current at and above which the accuracy requirements under this regulation fully apply up 
to Imax 
1.8.4  
maximum current, Imax 
the highest value of current at which the electricity meter still meets the accuracy requirements laid 
down by this r egulation  
1.8.5  
base current, Ib 
the value of current used as reference for the decisive properties of a direct connected electricity meter  
1.8.6  
nominal current, In 
in the case of a transformer operated electricity meter, this is the value of current for which the electricity 
meter was designed  
1.8.7  
reference current, Iref 
for direct connected electricity meters, this is 10 times the transitional current  
NOTE  1 This value is the same as base current Ib. 
for transformer operated electricity meters, this is  20 times the transitional current  
NOTE  2 This value is the same as nominal current In. General Measure No  0111 -OOP -C022 -18 
5 1.9 
reference voltage, Un 
the voltage value used as reference for the decisive properties of the electricity meter  
NOTE  More than one value may be used as reference vol tage.  
1.10 
reference frequency, fn 
the frequency value used as reference for the decisive properties of the electricity meter  
1.11 
maximum permissible error  
relative error limits in % given by the following formula:  
relative error (in %) =  energy registered by the electricity meter – actual energy  
 100 
actual energy  
2   Metrological requirements  
The metrological requirements for active energy meters intended for use in residential, commercial and 
light industrial environments are based on the requirements of the Government Regulation1, while 
applying the relevant requirements under harmonised standards.  
The metrological requirements for active energy meters intended for use in other than residential, 
commercial and light industrial environments  are either the same as those under the Government 
Regulation or, where this is not the case, the requirements under European standards have been adopted.  
The metrological requirements for reactive energy meters have been adopted from European standards.  
The metrological requirements for active energy meters bearing the EEC mark are based on the 
requirements applied during EEC type approval.  
The verification of electricity meters type approved pursuant to Act No  505/1990 on metrology, as 
amended, is subject  to the metrological requirements applicable at the time they were put into 
circulation.  
2.1   Rated operating conditions  
2.1.1    Voltage range  
Electricity meters must measure electrical energy within the limits of the maximum permissible errors 
across a r ange of voltages within ±10  % of the rated voltage.  
2.1.2    Frequency range  
Electricity meters must measure electrical energy within the limits of the maximum permissible errors 
across a range of frequencies within ±2  % of the rated frequency.  
2.1.3    Curr ent range  
Electricity meters smut measure electrical energy within the limits of the maximum permissible errors 
across a range of currents from Imin to Imax at cos  φ = 0.5 inductive to cos  φ = 0.8 capacitive, or 
sin φ = 0.5 inductive to sin  φ = 0.8 capacit ive. General Measure No  0111 -OOP -C022 -18 
6 2.1.4    Ambient temperature range  
Electricity meters must measure electrical energy within the limits of the maximum permissible errors 
across a range of ambient temperatures specified by the manufacturer.  
2.2   Maximum permissible errors  
2.2.1    Maximum permissible errors for electromechanical active energy meters of accuracy class 
0.5 at the time of type approval  
The maximum permissible errors for type approval given below apply only to electromechanical active 
energy meters of accuracy c lass 0.5 (these electricity meters are not covered by the Government 
Regulation as they are not intended for use in residential, commercial and light industrial environments).  
Under reference conditions, the relative errors of the electricity meters must n ot exceed the maximum 
permissible errors given in Tables  1 and 2.  
If the electricity meter is designed for bi -directional measurement of electrical energy, the values given 
in Tables  1 and 2 apply to both directions.  
Table  1 – Maximum permissible errors fo r single -phase and three -phase electricity meters of 
accuracy class 0.5 with symmetrical load  
Current  
Power factor  Relative error limits in %  for direct connected 
electricity meters  for transformer 
operated electricity 
meters  
0.05Ib ≤ I < 0.1 Ib 0.02In ≤ I < 0.05 In 1 ±1.0 
0.1Ib ≤ I ≤ Imax 0.05In ≤ I ≤ Imax 1 ±0.5 
0.1Ib ≤ I < 0.2 Ib 0.05In ≤ I < 0.1 In 0.5 inductive  
0.8 capacitive  ±1.3 
±1.3 
0.2Ib ≤ I ≤ Imax 0.1In ≤ I ≤ Imax 0.5 inductive  
0.8 capacitive  ±0.8 
±0.8 
Table  2 – Maximum permissible errors for  three -phase electricity meters of accuracy class 0.5 
with single -phase load, but with voltage circuits energised with symmetrical three -phase voltage  
Current  
Power factor  Relative error limits in 
% for direct connected 
electricity meters  for transformer 
operated electricity 
meters  
0.2Ib ≤ I < Ib 0.1In ≤ I ≤ In 1 ±1.5 
0.5 Ib 0.2 In 0.5 inductive  ±1.5 
Ib In 0.5 inductive  ±1.5 
Ib ≤ I ≤ Imax In ≤ I ≤ Imax 1 – General Measure No  0111 -OOP -C022 -18 
7 2.2.2    Maximum permissible errors for static active energy meters of accuracy class 0.2  S and  
0.5 S at the time of type approval  
The maximum permissible errors for type approval given below apply only to static active energy meters 
of accuracy class 0.2  S and 0.5  S (these electricity meters are not covered by the Government Regulation 
as they are not intended for use in residential, commercial and light industrial environments).  
Under reference conditions, the relative errors of the electricity meters must not exceed the maximum 
permissible errors given in Tables  3 and 4.  
If the electricity meter i s designed for bi -directional measurement of electrical energy, the values given 
in Tables  3 and 4  apply to both directions.  
Table  3 – Maximum permissible errors for single -phase and three -phase active energy meters of 
accuracy class 0.2  S and 0.5  S with symmetrical load  
Current  Power factor  Relative error limits in %  
for electricity meters of accuracy 
class  
0.2 S 0.5 S 
0.01In ≤ I < 0.05 In 1 ±0.4 ±1.0 
0.05In ≤ I ≤ Imax 1 ±0.2 ±0.5 
0.02In ≤ I < 0.1 In 0.5 inductive  
0.8 capacitive  ±0.5 
±0.5 ±1.0 
±1.0 
0.1In ≤ I ≤ Imax 0.5 inductive  
0.8 capacitive  ±0.3 
±0.3 ±0.6 
±0.6 
Table  4 – Maximum permissible errors for three -phase active energy meters of accuracy class 
0.2 S and 0.5  S with single -phase load, but with voltage circuits energised with symmetrical 
three -phase voltage  
Current  Power factor  Relative error limits in % for 
electricity meters of accuracy class  
0.2 S 0.5 S 
0.05In ≤ I ≤ Imax 1 ±0.3 ±0.6 
0.1In ≤ I ≤ Imax 0.5 inductive  ±0.4 ±1.0 
2.2.3    Maximum permissible errors for static electricity meters when measuring reactive energy  
The maximum permissible errors when measuring reactive energy apply only to accuracy tests 
performed when type approving static electricity meters intended for measurement of this type of 
energy, which is not covered b y the Government Regulation.  
Under reference conditions, the relative errors of the electricity meter must not exceed the maximum 
permissible errors given in Tables  5 and 6.  General Measure No  0111 -OOP -C022 -18 
8 Table  5 – Maximum permissible errors for single -phase and three -phase reactive ene rgy meters 
with symmetrical load  
Current  sin φ 
(inductive or 
capacitive)  Relative error limits in % for 
electricity meters of accuracy class  
for direct 
connected 
electricity meters  for transformer operated 
electricity meters  0.5 S 1 and 
1 S 2 3 
0.05Ib ≤ I < 0.1 Ib 0.02In ≤ I < 0.05 In 1 ±1.0 ±1.5 ±2.5 ±4.0 
0.1Ib ≤ I ≤ Imax 0.05In ≤ I ≤ Imax 1 ±0.5 ±1.0 ±2.0 ±3.0 
0.1Ib ≤ I < 0.2 Ib 0.05In ≤ I < 0.1 In 0.5 ±1.0 ±1.5 ±2.5 ±4.0 
0.2Ib ≤ I ≤ Imax 0.1In ≤ I ≤ Imax 0.5 ±0.5 ±1.0 ±2.0 ±3.0 
Table  6 – Maximum permissible errors for three -phase electricity meters with single -phase load, 
but with voltage circuits energised with symmetrical three -phase voltage  
Current  sin φ 
(inductive or 
capacitive)  Relative error limits in % for 
electricity meters of accuracy cla ss 
for direct connected 
electricity meters  for transformer operated 
electricity meters  0.5 S 1 and 
1 S 2 3 
0.1Ib ≤ I ≤ Imax 0.05In ≤ I ≤ Imax 1 ±0.7 ±1.5 ±3.0 ±4.0 
0.2Ib ≤ I ≤ Imax 0.1In ≤ I ≤ Imax 0.5 ±1.0 ±2.0 ±3.0 ±4.0 
2.2.4    Maximum permissible errors at the time of verification  
When verified under reference conditions, electricity meters must not exceed the error limits for the 
individual types of electricity meters and the currents used given in Tables  25 to 31.  
2.3   No-load condition  
When the re is no current flowing through the electricity meter, it must not register any energy.  
2.4   Electricity meter start -up 
2.4.1    Start -up of active energy meters  
The electricity meter must start to measure and continue to register active energy at referen ce voltage 
Un, power factor  = 1 and the current given in Table  7 or 8, as applicable.  
Table 7  – Inrush currents for accuracy classes 0.2  S; 0.5  S; 0.5; 1 and  2 
Electricity meter  Accuracy class  
0.2 S 0.5 S 0.5 1 and 1  S 2 
Electromechanical, direct connected  – – 0.003 Ib 0.004 Ib 0.005 Ib 
Electromechanical, transformer operated  – – 0.002 In 0.002 In 0.003 In 
Static, direct connected  – 0.001 Ib – 0.004 Ib 0.005 Ib 
Static, transformer operated  0.001 In 0.001 In – 0.002 In 0.003 In General Measure No  0111 -OOP -C022 -18 
9 Table  8 – Inrush currents for classes A, B and C  
Electricity meter  Class  
A B C 
Electromechanical, direct connected  0.05Itr 0.04Itr – 
Electromechanical, transformer operated  0.06Itr 0.04Itr – 
Static, direct connected  0.05Itr 0.04Itr 0.04Itr 
Static, transformer operated  0.06Itr 0.04Itr 0.02Itr 
2.4.2    Start -up of reactive energy meters  
The electricity meter must start to measure and continue to register reactive energy at rated voltage Un, 
power factor  = 1 and the current given in Table  9. 
Table 9  – Inrush currents for accuracy classes 0.5  S; 1; 1  S; 2 and 3  
Electricity meters for  Accuracy class  
0.5 S 1 and 1  S 2 3 
Direct connected  0.002 Ib 0.004 Ib 0.005 Ib 0.010 Ib 
Transformer operated  0.001 In 0.002 In 0.003 In 0.005 In 
3   Technical requirements  
The technical requirements for active energy meters intended for use in residential, commercial and light 
industrial environments are based on the requirements of the Government Regulation1, while applying 
the relevant requirements under harmonised standards.  
The technical requirements for active energy meters intended for use in other than residential, 
commercial and light industrial environments are either the same as those under the Government 
Regulation or, where this is not the case, the requirements under European standards have be en adopted.  
The technical requirements for reactive energy meters have been adopted from European standards.  
The verification of electricity meters type approved pursuant to Act No  505/1990 on metrology, as 
amended, is subject to the metrological requireme nts applicable at the time they were put into 
circulation.  
3.1   Electricity meter design  
Electricity meters must be designed to maintain adequate stability of their metrological characteristics 
throughout the intended period of use (this period is estimat ed by the manufacturer), provided that they 
are properly installed, maintained and used according to the manufacturer’s instructions when in the 
environmental conditions for which they are intended.  
3.2   Housing  
Electricity meters must have a housing that  can be sealed so that the internal parts of the meter cannot 
be accessed without damaging the seal(s).  
The outer housing must not be removable without using a tool.  
The mechanical strength of the  electricity meter's housing must be such that any temporar y deformation 
does not prevent the meter from operating correctly.  General Measure No  0111 -OOP -C022 -18 
10 3.3   Counter  
Electricity meters must be equipped with a metrologically controlled counter.This may be a mechanical 
device in the form of cylinders or an electronic display.  
Electricity meters intended for measuring multiple types of energy must indicate which energy is 
currently being measured.  
Multi -tariff electricity meters must indicate which rate is currently in effect.  
The counter’s indications must correspond to rotor revolutions, the number of test diode pulses or the 
number of remote measurement pulses.This relationship is given by a constant indicated on the 
electricity meter’s label.  
The total energy counter must have a sufficient number of digits to ensure that when the electri city meter 
is operated at full load ( I = Imax, U = Un and cos  φ (or sin  φ) = 1) for 4  000 hours, the indication does not 
return to its initial value.It must not be possible to zero the total counter or the tariff counter without 
removing the seals.  
In the event of a power outage, the amount of electrical energy measured must remain identifiable for 
at least four months.  
Software  
Software critical for metrological characteristics must be identifiable and must be secure.The software 
must be easy to identify d irectly through the electricity meter.Evidence of any unauthorised intervention 
must be available.During the service life of the electricity meter, the software can be replaced by other 
approved type of software, but only by the manufacturer.  
In the case o f electricity meters where the software version cannot be read electronically (they have no 
LCD display or communication interface), the software version must be indicated on the electricity 
meter.  
3.5   Ancillary devices  
The metrological characteristics o f the meter may not be affected in any way by connecting an ancillary 
device to it, by a property of the connected ancillary device or a remotely connected ancillary device 
that communicates with the meter.  
3.6   Mechanical requirements  
The mechanical envi ronment for which the electricity meter is intended must be specified by the 
manufacturer.  
Electricity meters must be designed and built to prevent any danger in normal use and under normal 
conditions; particularly the following must be ensured:  
 safety of persons from electric shock;  
 safety of persons from the effects of excessive heat;  
 protection against propagation of fire;  
 protection against the ingress of solid objects, dust and water.  
3.7   Climatic conditions  
The manufacturer must specify the upper an d lower temperature limits for the rated operating range, 
limit operating range and for storage and transport.  General Measure No  0111 -OOP -C022 -18 
11 3.8   Electrical requirements  
3.8.1    Temperature rise  
Under nominal operating conditions, the electrical circuits and insulation must not reach a temperature 
that could negatively affect the operation of the electricity meter.  
3.8.2    Insulation  
The electricity meter and its built -in ancillary devices, if any, must maintain adequate insulation 
properties under normal conditions, taking into account the influences of the external environment and 
the different voltages that they are subjected to under normal conditions.  
3.8.3    Influence of short -circuit overcurrents  
Short -circuit overcurrents must not damage the electricity meter.Once the orig inal working conditions 
have been restored, the electricity meter must operate correctly and the error shift at reference current 
and unity power factor must not exceed the values given in Table  10. 
3.9   Electromagnetic compatibility  
The electricity meter  must conform to class E2 electromagnetic environment and also meet the following 
requirements.  
During and immediately after an electromagnetic disturbance  
a) any output intended for testing the accuracy of the electricity meter must not produce pulses or 
signals corresponding to an energy of more than the critical change value;  
b) and within reasonable time after the effects of the fault the electricity meter must:  
 recover to operate within the limits of the maximum permissible error (MPE),  
 provide all measurement functions,  
 allow recovery of all measurement data present before the effects of the fault started,  
 not indicate a change in the registered electrical energy of more than the critical change value.  
The critical change value x, in kWh, is given b y the equation:  
x = m · Un· Imax · 10–6 (1) 
where m is the number of measuring elements of the electricity meter, Un is in volts and Imax is in 
amperes).  
3.10   Resistance to unauthorised tampering  
The electricity meter must be designed so that any mechani cal tampering with the housing, window or 
terminal cover that can affect measurement accuracy causes visible permanent damage to the meter or 
the official or security markings, thus providing evidence of unauthorised tampering.  
Software, unauthorised modification of which over a communication interface is possible, must be 
protected.  
Software is distinguished as legally relevant software (LRS – formerly the metrological core of the 
software) and legally non -relevant software (LNRS – formerly applicatio n software).LNRS may be 
modified without damaging seals as long as the modification does not affect the CRC value.  
LRS:For example, the transformation ratio of the measuring transformers, the tariff tables, time, 
constants, method of counting energy (e.g. as a sum of absolute values or division according to demand 
and supply) may only be modified after breaking the seals and changing the position of a 
switch.Password protection alone is not sufficient.  General Measure No  0111 -OOP -C022 -18 
12 LRNS:For example, display brightness, inversion of line s on the LCD panel, removal of certain lines on 
the LCD panel.  
4   Marking of electricity meters  
At least the following information must be provided on the electricity meter:  
a) the manufacturer’s name or trademark;  
b) in the case of electricity meters manufactu red pursuant to Government Regulation No  464/2005 
and No  120/2016, the manufacturer’s address must be included;  
c) type designation;  
d) serial number and year of manufacture;  
e) designation of the electricity meter’s class;  
f) reference voltage;  
g) reference (or base or nominal) current;  
h) maximum current;  
i) minimum current (not required for electricity meters approved before the Government Regulation 
entered into force);  
j) reference frequency;  
k) the electricity meter’s constant;  
l) rated operating temperature range (not required fo r electricity meters approved before the 
Government Regulation entered into force);  
m) type of transmission grid (graphic symbol);  
n) a square -in-square symbol for fully insulated protective class II electricity meters (if applicable);  
o) a circuit diagram for conn ecting the electricity meter to the grid (it need not be provided on the 
identification label, but can for example be on the terminal cover).  
In addition, electricity meters must bear a mark demonstrating how they were placed on the market:  
a) the type -approv al mark according to Act No  505/1990 on metrology, as amended, or the EEC 
type-examination certificate according to the Government Regulation;also, the approval mark 
according to the MID;  
b) the ‘CE’ conformity mark for electricity meters approved prior to the entry into force of the 
Government Regulation;  
c) the ‘CE’ conformity mark and additional metrological markings for electricity meters approved 
according to the Government Regulation.  
4.2   Placement of the official mark  
The placement of official marks is  specified in the type approval certificate or the EC type -examination 
certificate, or other document used in the context of conformity assessment when placing the meter on 
the market and putting it into use.  
5   Type approval of measuring instruments  
Pursuant to Act No  505/1990 on metrology, as amended, class  A, B and C active energy meters intended 
for use in residential, commercial and light industrial environments are not subject to type General Measure No  0111 -OOP -C022 -18 
13 approval.These measuring instruments are placed on the market and put into use with conformity 
assessment in accordance with the Government Regulation1. 
Only the following meters are subject to type approval pursuant to Act No  505/1990 on metrology, as 
amended:  
a) active energy meters intended for use other than in resident ial, commercial and light industrial 
environments  
b) reactive energy meters of class 0.5  S, 1, 1  S, 2 and 3, or the reactive energy measurement functions 
of electricity meters intended for measuring multiple types of energy.  
5.1   In general  
The process of ty pe approval of electricity meters comprises the following tests:  
a) external inspection;  
b) tests of resistance of the electricity meter to mechanical influences;  
c) tests of resistance to environmental influences;  
d) tests of the effects of electrical properties;  
e) electromagnetic compatibility (EMC) tests;  
f) functional tests.  
5.2   External inspection  
The following is assessed by external inspection of the electricity meter:  
 the completeness of the required technical documentation;  
 conformity of the metrological and technical characteristics specified by the manufacturer in the 
documentation with the requirements of this regulation as specified in Articles  2 and 3;  
 the completeness and condition of the electricity meter according to the prescribed technical 
documentation;  
 conformity of the software version of the electricity meter with the version specified by the 
manufacturer.  
5.3   Performance of tests at the time of type approval  
5.3.1    Requirements for test equipment  
A measurement stations for testing el ectricity meters must be equipped with a reference electricity meter 
that has valid metrological traceability.The measurement station as a whole must have been verified by 
means of a 'station functional test'.  
The test equipment must allow for electricity meter errors to be determined with an uncertainty of no 
more than 1/5 of the relative error limits given in Tables  1 to 6.When testing Class 0.2  S electricity 
meters, 1/4 of these error limits is sufficient.  
5.3.2    Reference conditions for testing  
The tes ts must be performed under reference conditions with the electricity meter cover in place and the 
meter connected to test equipment according to the schematic diagram provided by the manufacturer.  
The reference conditions are subject to the values given in  Tables  21 to 23.  
In addition to the conditions specified above, there must be no disruptive mechanical vibrations in the 
laboratory.  General Measure No  0111 -OOP -C022 -18 
14 5.3.3    Preparation of electricity meters for testing  
Prior to testing, electricity meters must be allowed to thermally st abilise for a period of at least 6  hours 
in a room with a temperature of (23  ±5) °C. 
In order to reach operating temperature, prior to the performance of individual tests, the electricity 
meter's electrical circuitry must first be connected to reference vo ltage for at least:  
30 minutes, in the case electromechanical electricity meters;  
5 minutes, in the case of static electricity meters.  
5.4   Tests of resistance of the electricity meter to mechanical influences  
5.4.1    Spring hammer test  
The test of mechanical strength of the electricity meter’s housing must be performed using a spring -
actuated hammer on the electricity meter, which is mounted in its normal operating position.  
The spring hammer must exert a kinetic energy of 0.2  J ±0.02  J on the exter nal surface of the electricity 
meter’s outer housing (including windows) and on the terminal cover.  
The meter will pass this test if its housing and terminal cover is not damaged to an extent that could 
affect the functionality of the electricity meter and  allow contact with live parts.Minor damage that does 
not reduce the meter's protection from indirect contact or from ingress of solid objects, dust and water 
is permitted.  
5.4.2    Shock test  
The shock resistance test must be performed using half -sine puls es with a peak acceleration of 30 gn 
(300 m/s2) and pulse duration of 18  ms with the electricity meter in a non -operating state.The shocks 
must be applied to the electricity meter fastened to the test device in all three axes and in both directions.  
After t he test, the electricity meter must not exhibit any damage or changes in data, and must operate 
correctly in accordance with requirements.  
5.4.3  Vibration (sinusoidal) test  
The test of resistance to sinusoidal vibrations must be performed by subjecting an electricity meter in a 
non-operating state to sinusoidal vibrations at a frequency of 10  Hz to 150  Hz with a transient frequency 
of 60  Hz, where for:  
f < 60 Hz, the constant movement amplitude is 0.075  mm; 
f > 60 Hz, constant acceleration is 9.8  m/s2. 
The test is performed at a single check point using 10 repeating cycles per axis.  
After the test, the electricity meter must not exhibit any damage or changes in data, and must operate 
correctly in accordance with requirements.  
5.4.4    Heat and fire resistance  test 
The electricity meter’s terminal block, terminal cover and housing must provide sufficient protection 
against propagation of fire.They should not ignite if the live parts that are in contact with them become 
excessively hot.  
The heat and fire resista nce test must be performed by applying a hot loop to the terminal block at a 
temperature of 960  °C ±15 °C, and to the terminal cover and housing of the electricity meter at a 
temperature of 650  °C ±10 °C.The hot loop is applied for 30  s ±1 s. 
The contact w ith the hot loop may occur at an arbitrary location.If the terminal block is an integral part 
of the housing of the electricity meter, it is sufficient to perform this test only on the terminal block.  General Measure No  0111 -OOP -C022 -18 
15 5.4.5    Test of resistance to ingress of dust and water  
The tests of resistance to ingress of dust and water must be performed with the electricity meter in a 
non-operating state, mounted on an artificial wall.The supply cables are attached to the electricity 
meter’s terminals and the terminal cover is in plac e. 
The electricity meter must meet protection grade IP51 for indoor use and protection grade IP54 for 
outdoor use.  
5.4.5.1    Test of resistance to ingress of dust  
For indoor electricity meters, the same atmospheric pressure is maintained both inside and ou tside the 
electricity meter (neither negative nor positive pressure).  
Dust may enter the electricity meter only in quantities that do not compromise its operation.The 
electricity meter must subsequently pass the electrical insulation strength test referred  to in Article  5.6.2.  
5.4.5.2    Test of resistance to ingress of water  
Water may enter the electricity meter only in quantities that do not compromise its operation.The 
electricity meter must subsequently pass the electrical insulation strength test referred to in Article  5.6.2.  
5.5   Tests of resistance to climatic influences  
5.5.1    Dry heat test  
The dry heat test must be performed with the electricity meter in a non -operating state by gradually 
changing the ambient temperature to +70  °C ±2°C and exposing the meter to this temperature for 
72 hours.  
After the test is completed, the electricity meter must not exhibit any damage or changes in data and 
must function properly.  
5.5.2    Cold test  
The cold test must be performed with the electricity meter in a non -operating state using the Ab method 
according to ČSN EN 60068 -2-1 by gradually changing the temperature.  
Indoor electricity meters are exposed to an ambient temperature of −25  °C ±3 °C for 72  hours; outdoor 
electricity meters are exposed to an amb ient temperature of −40  °C ±3 °C for 16  hours.  
After the test is completed, the electricity meter must not exhibit any damage or changes in data and 
must function properly.  
5.5.3    Cyclic damp heat test  
The cyclic damp heat test must be performed on an ele ctricity meter without current, but with voltage 
and auxiliary circuits connected to a reference voltage.  
Indoor electricity meters are exposed to an ambient temperature of +40  °C ±2 °C and outdoor electricity 
meters are exposed to an ambient temperature o f +55  °C ±2 °C, for 12  hours.Subsequently, they are 
exposed to an ambient temperature of +25  °C ± 3 °C, also for 12  hours (12  h + 12  h cycle).In both cases, 
relative humidity is 95  %.The test duration is six cycles.  
After 24  hours of completing the test, t he electricity meter must be subjected to the following tests:  
a) the test of electrical insulation strength referred to in Article  5.6.2, with impulse voltage 
multiplied by a factor of 0.8;  
b) functional test; the electricity meter must not exhibit any damage o r changes in data, and must 
operate properly.  
The damp heat test also serves as a corrosion test.The result is assessed visually.There must be no visible 
signs of corrosion that could affect the functional characteristics of the electricity meter.  General Measure No  0111 -OOP -C022 -18 
16 5.5.4    Test of resistance to sunlight  
The sunlight resistance test is performed only on outdoor electricity meters in a non -operating state.The 
electricity meter is exposed to light for 8  hours and then kept in the dark for 16  hours (8  h + 16  h 
cycle).The upper a mbient temperature is kept at +55  °C.The duration of the test is three cycles.  
After the test, the external appearance and, in particular, the legibility of markings must not be 
changed.The operation of the electricity meter must not be compromised.  
5.6  Tests of the effects of electrical characteristics  
5.6.1   Temperature rise tests  
The temperature rise test must be performed by loading every current circuit with the maximum current 
Imax and every voltage circuit with 1.15 Un, for 2  hours.During the t est, the temperature of the outer 
surface may not rise by more than 25  K at an ambient temperature of +40  °C. 
After the test, the electricity meter must not exhibit any damage and must pass the electrical insulation 
strength tests referred to in Article  5.6.2. 
5.6.2    Electrical insulation strength tests  
5.6.2.1    In general  
The tests are performed on complete electricity meters, with the top cover of the terminal block in place 
and with terminal screws screwed into the core of a conductor with the maximum usable diameter.  
During the voltage impulse tests and alternating voltage tests, circuits not under test must be connected 
to earth.  
No penetration or flashover may occur during the test.After this test, an accuracy test must not reveal 
any error shift.  
5.6.2.2    Impulse voltage test  
Electrical insulation strength tests are performed using impulse voltage in individual circuits, between 
circuits and relative to earth.  
The impulse source must be capable of generating a normalised voltage impulse of 1.2/50  μs with a rise 
time of ±30  %, a fall time of ±20  % , energy of 0.5  J ±0.05  J, and an impedance of 500  Ω ±50 Ω. 
The test voltages must be as follows:  
 for protective class I electricity meters:  4 kV (for Un ≤ 300 V) and 1.5  kV (for Un ≤ 100 V); 
 for protective class II electricity meters:  6 kV (for Un ≤ 300 V) and 2.5  kV (for Un ≤ 100 V). 
For each test, the impulse voltage is always applied ten times with one polarity and then ten times for 
the other polarity.The minimum time between impulses must be 3 seconds.  
5.6.2.3    AC voltage test  
The AC voltage test is performed using voltage at a frequency of 45  Hz to 65  Hz for one minute.The 
voltage is applied between  
a) all voltage, current and auxiliary circuits connected together and the ground;  
b) circuits that are not interconnected while the electricity meter is in use.  
The test voltages must be as follows:  
 for protective class I electricity meters:  2 kV; 
 for protective class II electricity meters:  4 kV (test a), 2  kV (test b).  General Measure No  0111 -OOP -C022 -18 
17 5.6.3    Short -circuit test  
The short -circuit test must be performed using the currents pursuant to Table  10, applied for the 
specified period.  
Table  10 – Short -circuit currents  
Electricity meter  Accuracy 
class  Short -
circuit 
current  Period of 
application  Permissible 
error shift  
Electromechanical transformer operated active 
energy meter  0.5 20Imax 0.5 s ±0.3 % 
Static direct connected active energy meter  1 and 2  30Imax ½ cycle  ±1.5 % 
Static transformer operated active energy meter  1 and 2  20Imax 0.5 s ±0.5 % 
Static transformer operated active energy meter  0.2 S, 0.5  S 20Imax 0.5 s ±0.05  % 
Static direct connected reactive energy meter  1, 2 and 3  30Imax ½ cycle  ±1.5 % 
Static reactive transformer operated energy 
meter  2 and 3  20Imax 0.5 s ±1.5 % 
Static reactive transformer operated energy 
meter  1 S 20Imax 0.5 s ±0.5 % 
Static reactive transformer operated energy 
meter  0.5 s 20Imax 0.5 s ±0.05  % 
After short -term application of short -circuit overcurrents and thermal stabilisation, the error at nominal 
current and unity power factor is measured.The error shift compared to its value before the test must be 
less than the values given in the table.  
5.7   Electromagnetic compatibility tests  
5.7.1    Tests of immunity to voltage dips and short interruptions  
The tests of immunity to voltage dips and short interruptions must be performed on the electricity meter 
with voltage and auxiliary circuits connected to reference voltage and without any current in the current 
circuits.  
The following tests are performed:  
a) three voltage interruptions Δ U = 100 % Un for one second with a recovery time of 50  ms between 
the interruptions;  
b) one voltage interruption Δ U = 100 % Un for the period of one cycle at the reference frequency;  
c) one voltage dip Δ U = 50 % Un for one minute.  
The application of voltage dips and short interruptions must not cause a change in the counter greater 
than x units and the test output must not send a signal corresponding to more than x units.  
5.7.2    Electrostatic discharge immunity tests  
The tests of immunity to electrostatic dischar ges must be performed on the electricity meter with voltage 
and auxiliary circuits connected to reference voltage and without any current in the current circuits.The 
meter is tested as a table -top instrument.  
Ten contact discharges of 8  kV are applied to t he metal part of the housing or ten air discharges of 15  kV 
are applied to a part of the housing made of insulating material (for protective class II electricity meters).  
The application of the electrostatic discharges must not cause a change in the counte r greater than x units 
and the test output must not send a signal corresponding to more than x units.  General Measure No  0111 -OOP -C022 -18 
18 Temporary deterioration or loss of functionality or performance is allowed during the test.  
5.7.3    Tests of immunity to radiated, radio -frequency electro magnetic fields  
This test must not be performed on electromechanical electricity meters.  
The test must be performed for interference in the frequency range of 80  MHz to 2  000 MHz with 80  % 
AM modulation at 1  kHz sine wave.The meter is tested as a table -top instrument.  
5.7.3.1    Current test  
Voltage and auxiliary circuits are connected to reference voltage, current circuits are connected to a 
reference (or nominal, base) current, cos  φ (or sin  φ) = 1.The strength of the non -modulated test field is 
10 V/m.  
During the test, the operation of the electricity meter must not be subject to any disturbance.Additional 
error must not exceed the permissible values in Table  11. 
Table  11 – Critical change values for tests of immunity to radio -frequency electromagnetic fie lds 
Electricity meter  Accuracy class  Critical change value  
Active static  2 ±3 % 
Active static  1 ±2 % 
Active static  0.5 S ±1 % 
Active static  0.2 S ±1 % 
Reactive static  2 and 3  ±3 % 
Reactive static  1 and 1  S ±2 % 
Reactive static  0.5 s ±2 % 
5.7.3.2    No-current test  
Voltage and auxiliary circuits are connected to reference voltage, current circuits are without current 
(open circuit).The strength of the non -modulated test field is 30  V/m.  
The application of the radio -frequency field must not cause a cha nge in the counter greater than x units 
and the test output must not send a signal corresponding to more than x units.  
Temporary deterioration or loss of functionality or performance is allowed during the test.  
5.7.4    Tests of immunity to electrical fast transient/burst disturbances  
The tests of immunity to electrical fast transient/burst disturbances must be performed on the electricity 
meter with voltage and auxiliary circuits connected to reference voltage.Current circuits are connected 
to reference cur rent, cos  φ (or sin  φ) = 1.The meter is tested as a table -top instrument.  
The cable length between the coupling device and the electricity meter is 1  metre.The repetition 
frequency is 5  kHz and the duration of the test is 60  seconds for each polarity.  
A test voltage of 4  kV must be applied to voltage circuits and current circuits, if separated from the 
voltage circuits in normal operation.A test voltage of 2  kV must be applied to auxiliary circuits with a 
reference voltage over 40  V. 
Temporary deterioration  or loss of functionality or performance is allowed during the test.Additional 
error must not exceed the permissible critical change values in Table  12. General Measure No  0111 -OOP -C022 -18 
19 Table  12 – Critical change values for tests of immunity to electrical fast transient/burst 
disturbances  
Electricity meter  Accuracy class  Critical change value  
Active static  2 ±6 % 
Active static  1 ±4 % 
Active static  0.5 S ±2 % 
Active static  0.2 S ±1 % 
Reactive static  2 and 3  ±4 % 
Reactive static  1 and 1  S ±3 % 
Reactive static  0.5 s ±2 % 
5.7.5    Tests  of immunity to conducted disturbances induced by radio -frequency fields  
The tests of immunity to conducted disturbances induced by radio -frequency fields must be performed 
on the electricity meter with voltage and auxiliary circuits connected to reference  voltage.Current 
circuits are connected to reference current, cos  φ (or sin  φ) = 1.The meter is tested as a table -top 
instrument.The frequency range of the disturbances is 150  kHz to 80  MHz and the disturbance voltage 
is 10  V. 
During the test, the function  of the electricity meter must not be perturbed and the additional relative 
error must not exceed the critical change values in Table  13. 
Table  13 – Critical change value for the test of immunity to conducted disturbances induced by 
radio -frequency fields  
Electricity meter  Accuracy class  Critical change value  
Active static  2 ±3 % 
Active static  1 ±2 % 
Active static  0.5 S ±2 % 
Active static  0.2 S ±1 % 
Reactive static  2 and 3  ±3 % 
Reactive static  1 and 1  S ±2.5 % 
Reactive static  0.5 s ±1.5 % 
5.7.6    Tests of immunity to surges  
The tests of immunity to surges must be performed on the electricity meter with voltage and auxiliary 
circuits connected to reference voltage and without any current in the current circuits.  
The cable length between the surge generator and the electricity meter is 1  metre and it is tested in 
differential mode (phase –phase).  
Surges with a phase shift of 60° and 240° relative to the AC zero crossing point are applied.A test voltage 
of 4 kV is used to test current and voltag e circuits, and 1  kV is used to test auxiliary circuits with a 
reference voltage over 40  V. 
Five positive and five negative impulses are applied at a repetition rate of not more than 1/min.  
The application of the surge impulse must not cause a change in th e counter greater than x units and the 
test output must not send a signal corresponding to more than x units.  General Measure No  0111 -OOP -C022 -18 
20 Temporary deterioration or loss of functionality or performance is allowed during the test.  
5.7.7    Tests of immunity to damped oscillatory waves  
The tests of immunity to damped oscillatory waves must be performed only for transformer operated 
electricity meters intended for use in electrical power plants and high -voltage substations.  
The tests must be performed on the electricity meter with voltage  and auxiliary circuits connected to a 
reference voltage of >40  V.Current circuits are connected to reference current, cos  φ (or sin  φ) = 1.The 
meter is tested as a table -top instrument.  
Damped oscillatory waves with a frequency of 100  kHz (repetition rate  of 40  Hz) and 1  MHz (repetition 
rate of 400  Hz) are applied to voltage and auxiliary circuits with a common -mode voltage of 2.5  kV and 
a differential voltage of 1.0  kV. 
The test duration is 60 seconds (15 cycles with 2  s on, 2  s off, for each frequency).  
During the test, the function of the electricity meter must not be perturbed and the additional relative 
error must not exceed the critical change values in Table  14. 
Table  14 – Critical change value during test of resistance to damped oscillatory wave  
Electricity meter  Accuracy class  Critical change value  
Active static  2 ±3 % 
Active static  1 ±2 % 
Active static  0.5 S ±2 % 
Active static  0.2 S ±1 % 
Reactive static  2 and 3  ±4 % 
Reactive static  1 and 1  S ±3 % 
Reactive static  0.5 s ±2 % 
5.7.8    Tests of immunity to alternating magnetic fields of external origin  
The tests of immunity to alternating magnetic fields of external origin must be performed on the 
electricity meter connected to a reference voltage and reference current, cos  φ (or sin  φ) = 1.The meter 
is tested as a table -top instrument.  
An alternating magnetic field of  0.5 mT at the reference frequency is applied to the electricity meter in 
three perpendicular planes.  
During the test, the function of the electricity meter must not be perturbed and the additional relative 
error must not exceed the critical change values in Table  15. 
Table  15 – Critical change value during the test of immunity to alternating magnetic fields of 
external origin  
Electricity meter  Accuracy class  Critical change value  
Active static  2 ±3 % 
Active static  1 ±2 % 
Active static  0.5 S ±1 % 
Active static  0.2 S ±0.5 % 
Reactive static  2 and 3  ±3 % 
Reactive static  1 and 1  S ±2 % General Measure No  0111 -OOP -C022 -18 
21 Reactive static  0.5 s ±1 % 
5.7.9    Immunity to direct magnetic fields of external origin  
The tests of immunity to direct magnetic fields of external origin must be performed on the electricity 
meter connected to a reference voltage and reference current, cos  φ (or sin  φ) = 1.A direct magnetic field 
with a magnetomotive force of Fm = 1 000 A is gra dually applied to all accessible surfaces of the 
electricity meter.  
During the test, the function of the electricity meter must not be perturbed and the additional relative 
error must not exceed the critical change values specified in Table  16. 
Table  16 – Critical change value during the test of immunity to direct magnetic fields of external 
origin  
Electricity meter  Accuracy class  Critical change value  
Active static  2 ±3 % 
Active static  1 ±2 % 
Active static  0.5 S and 0.2  S ±2 % 
Reactive static  2 and 3  ±3 % 
Reactive static  1; 1 S and 0.5  S ±2 % 
5.7.10    Suppression of RF interference  
The tests of suppression of RF interference must be performed on the electricity meter with voltage and 
auxiliary terminals connected to reference voltage and with a current of 0.1 Iref and 0.2 Iref (or nominal, 
base), cos  φ (or sin  φ) = 1.The meter is tested as a class B table -top instrument.A 1 -m long unshielded 
cable must be used for each terminal to connect the voltage circuits.  
The emissions of radio -frequency inter ference conducted in the 0.15  MHz to 30 MHz frequency range 
and radiated in the 30  MHz to 1  GHz frequency range is measured.  
The test results must not exceed the limits for electromagnetic interference specified in the relevant 
technical standard.  
5.7.11    Test of immunity to conducted disturbances in the 2  kHz to 150  kHz band  
The tests of immunity to these disturbances must be performed on the electricity meter connected to 
reference voltage and with reference current Iref at 50  Hz.The interference current  (2–150) kHz of a 
magnitude according to Table  17 must be supplied from a separate source.The additional error of the 
electricity meter caused by the disturbance is measured.This error must be less than the permissible 
errors in Table  17. 
Table 17  – Maximu m permissible additional errors for direct and indirect connected electricity 
meters  
Maximum permissible additional errors for direct connected electricity meters  
Frequency range  Interference 
current value  current 50  Hz cos φ; 50  Hz Class A  Class B  Class C 
2 kHz to 30  kHz 2 A Iref >0.9 ±6 % ±4 % ±2 % 
30 kHz to 150  kHz 1 A Iref >0.9 ±6 % ±4 % ±2 % 
continued  General Measure No  0111 -OOP -C022 -18 
22 Table  17 – continued  
Maximum permissible additional errors for indirect connected electricity meters  
Frequency range  Interference 
current value  current 50  Hz cos φ; 50  Hz Class A  Class B  Class C  
2 kHz to 30  kHz 2 %·Imax Iref >0.9 ±6 % ±4 % ±2 % 
30 kHz to 150  kHz 1 %·Imax Iref >0.9 ±6 % ±4 % ±2 % 
 
5.8   Functional tests  
5.8.1    Test of no -load operation  
The test of no -load operation is performed  in accordance with Article  7.4. 
5.8.2    Start -up test  
The start -up test is performed in accordance with Article  7.5. 
5.8.3    Accuracy test  
The accuracy test is performed in accordance with Article 7.6.  
5.8.4    Test of ambient temperature influence  
The add itional error due to temperature change (within the rated operating range of the electricity meter) 
relative to the error under reference conditions must not exceed the limits for the given accuracy 
class.These limits are given in Table  18 in the form of t hermal coefficient limits in %/K.  
Table  18 – Thermal coefficient limits in %/K for the tests of ambient temperature influence on 
the electricity meter  
Grid 
connection  Load  Active energy meters – Static  
Current  Power 
factor  Accuracy class  
2 1 0.5 S 0.2 S 
direct  0.1In to Imax 
0.2In to Imax 1 
0.5 ind.  ±0.10  
±0.15  ±0.05  
±0.07  ±0.03  
±0.05  – 
– 
transformer 
operated  0.05In to Imax 
0.1In to Imax 1 
0.5 ind.  ±0.10  
±0.15  ±0.05  
±0.07  ±0.03  
±0.05  ±0.01  
±0.02  
 
Grid 
connection  Load  Active energy meters – Electromechanical  
Current  Power 
factor  Accuracy class  
2 1 0.5 
direct  0.1Ib to Imax 
0.2Ib to Imax 1 
0.5 ind.  ±0.10  
±0.15  ±0.05  
±0.07  ±0.03  
±0.05  
transformer 
operated  0.05In to Imax 
0.1In to Imax 1 
0.5 ind.  ±1.5 
±1.0 ±1.0 
±0.7 ±0.8 
±0.5 
continued  General Measure No  0111 -OOP -C022 -18 
23 Table  18 – continued  
Grid 
connection  Load  Reactive energy meters (static)  
Current  Power 
factor  Accuracy class  
3 2 1 and 1  S 0.5 S 
direct  0.05In to Imax 
0.10In to Imax 1 
0.5 ind.  ±0.15  
±0.25  ±0.10  
±0.15  ±0.05  
±0.10  – 
– 
transformer 
operated  0.02In to Imax 
0.05In to Imax 1 
0.5 ind.  ±0.15  
±0.25  ±0.10  
0.15 ±0.05  
±0.10  ±0.03  
±0.05  
5.8.5    Voltage change test  
The additional error due to a voltage change of ±10  %·Un relative to the error under reference conditions 
must not exceed the limits for the given accuracy class in Table  19. 
Table  19 – Additional error limits in % for the test with a voltage change of ±10  %·Un 
Grid 
connection  Load  Active energy meters – Static  
Current  Power 
factor  Accuracy class  
2 1 0.5 S 0.2 S 
direct  0.05In to Imax 
0.10In to Imax 1 
0.5 ind.  ±1.0 
±1.5 ±0.7 
±1.0 ±0.2 
±0.4 – 
– 
transformer 
operated  0.02In to Imax 
0.05In to Imax 1 
0.5 ind.  ±1.0 
±1.5 ±0.7 
±1.0 ±0.2 
±0.4 ±0.1 
±0.2 
 
Grid 
connection  Load  Active energy meters – Electromechanical  
Current  Power 
factor  Accuracy class  
2 1 0.5 
direct  0.1Ib 
0.5Imax 
0.5Imax 1 
1 
0.5 ind.  ±1.5 
±1.0 
±1.5 ±1.0 
±0.7 
±1.0 ±0.8 
±0.5 
±0.7 
transformer 
operated  0.1In 
0.5Imax 
0.5Imax 1 
1 
0.5 ind.  ±1.5 
±1.0 
±1.5 ±1.0 
±0.7 
±1.0 ±0.8 
±0.5 
±0.7 
 
Grid 
connection  Load  Reactive energy meters (static)  
Current  Power 
factor  Accuracy class  
3 2 1 and 1  S 0.5 S 
direct  0.05In to Imax 
0.10In to Imax 1 
0.5 ind.  ±2.0 
±3.0 ±1.0 
±1.5 ±0.5 
±1.0 – 
– 
transformer 
operated  0.02In to Imax 
0.05In to Imax 1 
0.5 ind.  ±2.0 
±3.0 ±1.0 
±1.5 ±0.5 
±1.0 ±0.25  
±0.5 General Measure No  0111 -OOP -C022 -18 
24 5.8.6    Frequency change test  
The additional error due to a frequency change of ±2  %·fn relative to the error under reference conditions 
must not exceed the limits for the given accuracy class in Table  20. 
Table  20 – Additional error limits in % for the test with a frequency change of ±2  %·fn 
Grid 
connection  Load  Active energy meters – Stati c 
Current  Power 
factor  Accuracy class  
2 1 0.5 S 0.2 S 
direct  0.05In to Imax 
0.10In to Imax 1 
0.5 ind.  ±0.8 
±1.0 ±0.5 
±0.7 ±0.2 
±0.2 – 
– 
transformer 
operated  0.02In to Imax 
0.05In to Imax 1 
0.5 ind.  ±0.8 
±1.0 ±0.5 
±0.7 ±0.2 
±0.2 ±0.1 
±0.1 
 
Grid 
connection  Load  Active energy meters – Electromechanical  
Current  Power 
factor  Accuracy class  
2 1 0.5 
direct  0.1Ib 
0.5Imax 
0.5Imax 1 
1 
0.5 ind.  ±1.5 
±1.3 
±1.5 ±1.0 
±0.8 
±1.0 ±0.7 
±0.6 
±0.8 
transformer 
operated  0.1In 
0.5Imax 
0.5Imax 1 
1 
0.5 ind.  ±1.5 
±1.3 
±1.5 ±1.0 
±0.8 
±1.0 ±0.7 
±0.6 
±0.8 
 
Grid 
connection  Load  Reactive energy meters (static)  
Current  Power 
factor  Accuracy class  
3 2 1 and 1  S 0.5 S 
direct  0.05In to Imax 
0.10In to Imax 1 
0.5 ind.  ±2.5 
±2.5 ±2.5 
±2.5 ±0.5 
±1.0 ±0.25  
±0.5 
transformer 
operated  0.02In to Imax 
0.05In to Imax 1 
0.5 ind.  ±2.5 
±2.5 ±2.5 
±2.5 ±0.5 
±1.0 ±0.25  
±0.5 
5.8.7    Counter test  
The counter test is performed in accordance with Article  7.7. 
6   Initial verification  
Pursuant to Act No  505/1990 on metrology, as  amended, class  A, B and C active energy meters intended 
for use in residential, commercial and light industrial environments are not subject to initial 
verification.These measuring instruments are placed on the market and put into use with conformity 
assessment in accordance with the Government Regulation1. 
Only the following meters are subject to initial verification pursuant to Act No  505/1990 on metrology, 
as amended:  
a) class 0.2  S; 0.5  S; 0.5; 1 and  2 active energy meters;  General Measure No  0111 -OOP -C022 -18 
25 b) electricity meters intended for  use other than in residential, commercial and light industrial 
environments;  
c) class 0.5  S, 1, 1  S, 2 and 3 reactive energy meters or the reactive energy measurement functions 
of electricity meters intended for measuring multiple types of energy;  
d) class  2 active energy meters bearing the EEC mark;  
e) electricity meters which, at the given time, have a valid type approval certificate under the 
transitional provisions in §  9 of the Government Regulation;  
f) electricity meters after repair.  
Initial verification follow s a procedure identical to that used for subsequent verification referred to in 
Chapter  7. 
7   Subsequent verification  
Pursuant to Act No  505/1990 on metrology, as amended, all types and classes of electricity meters 
specified in this regulation are subjec t to subsequent verification.The manner in which the electricity 
meter was placed on the market and put into use is taken into account by specifying the accuracy 
requirements applied in verification according to the individual classes of electricity meters . 
7.1.   In general  
Subsequent verification of electricity meters must comprise the following tests:  
a) visual inspection;  
b) no-load operation test;  
c) start-up test;  
d) accuracy test;  
e) counter test.  
7.2   Visual inspection  
The purpose of visual inspection is to check  that the electricity meter submitted for verification, 
including the software version, conforms to the approved type or design of the meter for which 
conformity was declared when it was placed on the market.Attention must be paid to verifying the 
correctn ess of markings within the meaning of Article 4.1 and its legibility.  
The electricity meter is also inspected for mechanical damage; meters with an electronic display are 
checked to verify that all characters on the display are visible after the device is connected to the grid.  
Electricity meters which do not conform to the approved type or to the design for which conformity was 
declared when placing them on the market and electricity meters that are damaged are not tested further.  
7.3   Test conditions  
7.3.1    Requirements for test equipment  
Measurement stations for testing electricity meters must be equipped with a reference electricity meter 
that has a valid calibration record.The measurement station as a whole must have been verified via a 
station fun ctional test.  
The test equipment must allow electricity meter errors to be determined with an uncertainty less than or 
equal to 1/4 of the error limits in Tables  25 to 31.When testing class 0.2  S electricity meters, 1/3 of the 
error limit is sufficient.  
The equipment must also allow for clear verification of compliance with the requirements under 2.2, 2.3 
and 2.4.  General Measure No  0111 -OOP -C022 -18 
26 7.3.2    Reference test conditions  
The tests must be performed under reference conditions with the electricity meter cover in place and the 
meter connected to test equipment according to the schematic diagram provided by the manufacturer.  
The reference conditions specified in Tables  20 to 22 apply to the verification of electricity meters.  
In addition to the conditions specified above, there must be  no disruptive mechanical vibrations in the 
laboratory.  
Table  21 – Reference conditions for electromechanical active energy meters  
Influence factor  Reference value  Permissible tolerances for 
electricity meters of accuracy class  Permissible tolerances 
for electricity meters 
of class  
0.5 1 2 A B 
Ambient temperature  Reference 
temperature or, if 
not given, 23  °C ±1 °C ±2 °C ±2 °C ±2 °C ±2 °C 
Voltage  Reference voltage  ±0.5 % ±1.0 % ±1.0 % ±1.0 % ±1.0 % 
Frequency  Reference 
frequency  ±0.2 % ±0.3 % ±0.5 % ±0.5 % ±0.3 % 
Phase sequence  L1 – L2 – L3 – – – – – 
Voltage asymmetry  All phases 
connected  – – – – – 
Waveform  Sine voltage and 
currents  Distortion factor less than:  
2 % 2 % 3 % 3 % 2 % 
Direct magnetic field 
of external origin  Equal to zero  – – – – – 
Alternating magnetic 
field of external origin 
at grid frequency  Equal to zero  Induction value causing an error shift not greater than:  
±0.1 % ±0.2 % ±0.3 % ±0.3 % ±0.2 % 
Operation of ancillary 
devices  Ancillary device 
not in operation  – – – – – 
Operating position  Vertical operating 
position c ±0.5º  ±0.5º  ±0.5º  ±0.5°  ±0.5°  
Conducted interference 
induced by radio -
frequency 
electromagnetic fields, 
150 kHz to 80  MHz  Equal to zero  <1 V <1 V <1 V <1 V <1 V 
Table  22 – Reference conditions for static active energy meters  
Influence factor  Reference 
value  Permissible tolerances for electricity 
meters of accuracy class  Permissible tolerances for 
electricity meters of class  
0.2 S 0.5 S 1 2 A B C 
Ambient 
temperature  Reference 
temperature or, 
if not specified, 
23 °C ±2 °C ±2 °C ±2 °C ±2 °C ±2 °C ±2 °C ±2 °C General Measure No  0111 -OOP -C022 -18 
27 Voltage  Reference 
voltage  ±1.0 % ±1.0 % ±1 % ±1 % ±1.0 % ±1.0 % ±1.0 % 
Frequency  Reference 
frequency  ±0.3 % ±0.3 % ±0.3 % ±0.5 % ±0.5 % ±0.3 % ±0.3 % 
Phase sequence  L1 – L2 – L3 – – – – – – – 
Voltage 
asymmetry  All phases 
connected  – – – – – – – 
Waveform  Sine voltages 
and currents  Distortion factor less than:  
2 % 2 % 2 % 3 % 3 % 2 % 2 % 
Direct magnetic 
field of external 
origin  Equal to zero  – – – – – – – 
Alternating 
magnetic field of 
external origin at 
grid frequency  Equal to zero  Induction value causing an error shift not greater than:  
± 0.1 % or 
<0.05  mT ± 0.1 % or 
<0.05  mT ±0.2 % ±3 % ±0.3 % ±0.2 % ±0.1 % 
Electromagnetic 
radio -frequency 
fields, 30  kHz to 
2 GHz  Equal to zero  <1 V/m <1 V/m <1 V/m <1 V/m <1 V/m <1 V/m <1 V/m 
Operation of 
ancillary devices  Ancillary 
device not in 
operation  – – – – – – – 
Conducted 
interference 
induced by radio -
frequency 
electromagnetic 
fields, 150  kHz to 
80 MHz  Equal to zero  <1 V <1 V <1 V <1 V <1 V <1 V <1 V 
Table  23 – Reference conditions for static reactive energy meters  
Influence factor  Reference value  Permissible tolerances for electricity meters of 
accuracy class  
0.5 S 1 and 1  S 2 3 
Ambient temperature  Reference 
temperature or, if 
not specified, 
23 °C ±2 °C ±2 °C ±2 °C ±2 °C 
Voltage  Reference voltage  ±1.0 % ±1.0 % ±1.0 % ±1.0 % 
Frequency  Reference 
frequency  ±0.3 % ±0.3 % ±0.5 % ±0.5 % 
Phase sequence  L1 – L2 – L3 – – – – 
Voltage asymmetry  All phases 
connected  – – – – 
Waveform  Sine voltage  Non-linear distortion factor less than  
2 % 2 % 2 % 3 % General Measure No  0111 -OOP -C022 -18 
28 Direct magnetic induction of 
external origin  Equal to zero  – – – – 
Alternating magnetic induction 
of external origin at reference 
frequency  Magnetic induction 
equal to zero  Induction value  causing an error shift not greater 
than:  
±0.3 % ±0.3 % ±0.3 % ±0.3 % 
Electromagnetic radio -frequency 
fields, 30  kHz to 2  GHz  Equal to zero  <1 V/m <1 V/m <1 V/m <1 V/m 
Operation of accessories  Accessories not in 
operation  – – – – 
Conducted faults induced by 
electromagnetic fields, 150  kHz 
to 80  MHz  Equal to zero  <1 V <1 V <1 V <1 V 
7.3.3    Preparation of electricity meters for testing  
Prior to performing the metrological tests, the electricity meters must be allowed to thermally stabilise 
for at least 6  hours in a room with a temperature of (23  ±5) °C. 
In order to reach operating temperature, prior to performing the individual verification tests, the voltage 
circuits of the electricity meter must first be connected to reference voltage for at leas t: 
30 minutes, in the case electromechanical electricity meters;  
5 minutes, in the case of static electricity meters.  
7.4   Test of no -load operation  
7.4.1    Test of no -load operation for electromechanical electricity meters  
For electricity meters with a mechanical counter, only the lowest -order cylinder may be engaged.Prior 
to testing, electromechanical electricity meters are set so that the mark on the rotor is visible in the 
window.  
During the test, the voltage circuits are sequentially connected to the  following voltages:  
80 % of the reference voltage;  
110 % of the reference voltage;  
while the current circuits of the electricity meter are not energised.  
The test duration is at least 15  minutes for every voltage.  
The meter passes the test if the mark on the rotor does not leave the window.  
7.4.2    Test of no -load operation for static electricity meters  
In the case of static electricity meters, the voltage circuits are connected to 115  % of the reference 
voltage, while the current circuits of the electrici ty meter are not connected to power.The minimum test 
period is calculated using the equation:  
 (2) 
where  ..............  k   is the electricity meter constant (imp/kWh or imp/kvarh),  
Pmax   is the maximum output that can be measured by the electricity meter in W or var,  
the values of constant K0 are given in Table  24. 
General Measure No  0111 -OOP -C022 -18 
29 Table  24 – Values of constant K0 
Accuracy 
class  Active energy meters  Reactive energy meter  
2 1 0.5 S 0.2 S 3 2 1 and 1  S 0.5 S 
K0 480 600 600 900 300 480 600 600 
The minimum test period for class  A, B and C electricity meters is calculated using the formula:  
st test310 240
I Umkt
(3) 
where  ..............  k   is the electricity meter constant (imp/kWh),  
m   is the number of measuring elements,  
Utest   is the test voltage in volts,  
Ist   is the inrush current according to Table  8 in amperes.  
The test period for static electricity meters must be at least 15 minutes, even if the calculated time t is 
shorter.  
The meter passes the test if the test LED or pulse output for remote measurement ha s sent no pulse or 
no more than one pulse.  
7.5   Start -up test  
During the start -up test, the electricity meter must start measuring energy after being connected to 
reference voltage Un, at cos  φ (or sin  φ) = 1 and energising the current circuits according to Table  7, 8 
or 9.The revolution of the rotor or the pulses sent to the test output are observed.  
Different types of electricity meters are tested under additional conditions:  
 electromechanical electricity meters with a mechanical counter: no more than tw o cylinders may 
be engaged;  
 electromechanical electricity meters with a mechanical maximum meter: the maximum indicator 
may not be engaged;  
 electricity meter with multiple reference voltages: for electricity meters with multiple reference 
voltages or with the full range of reference voltages, the start -up test is performed at the maximum 
and minimum voltages specified on the label;  
 electricity meters with two base currents: the start -up test is performed at a starting current 
calculated from the smaller bas e current.  
Electromechanical electricity meters pass the test if the rotor has started rotating and made at least one 
revolution.The test is performed until the described conditions are met, but for no longer than the period 
it would theoretically take the  rotor of the tested electricity meter to make three revolutions (provided 
that it measures without errors at the starting current).  
Static electricity meters pass the test if the test LED or the pulse output for remote measurement has 
sent at least two pu lsesThe test is performed until the described conditions are met, but for no longer 
than the period it would theoretically take the test LED of the tested electricity meter or the pulse output 
for remote measurement to send at least three pulses (provided that it measures without errors at the 
starting current).This period is calculated in minutes using the equation  
∆t = 3∙6∙104
𝑘∙𝑚∙𝑈n∙𝐼st(4) General Measure No  0111 -OOP -C022 -18 
30 7.6   Accuracy test  
7.6.1    In general  
During the accuracy test, the electricity meter’s errors at the currents given in Tables  25 to 31 are 
established.The accuracy test must be performed using either:  
a) the method of recording the number of disc revolutions or pulses of the tested electricity meter, 
or 
b) the method of reading the data from the counter of the tested el ectricity meter.  
Prior to measuring the error at the given current settings, it is necessary to wait for at least 5  seconds.  
7.6.2    Measurement uncertainty  
The measurement error of electricity meters must be established with uncertainties smaller than 1/4  of 
the permissible error limits given in Tables  25 to 31.One exception are static electricity meters of 
accuracy class 0.2  S, for which the measurement uncertainties must be less than 1/3 of the permissible 
error limits given in Table  27. 
7.6.3    Specific  test requirements  
For electricity meters with a mechanical counter, only the lowest -order cylinder may be engaged during 
tests performed using the method of recording disc revolutions or pulses of the tested electricity 
meter.When using the method of read ing data from the counter, no more than the last two cylinders may 
be engaged.  
Electricity meters with and without ancillary devices are subject to the same test conditions and the same 
error limits.One exception are electricity meters with a mechanical an cillary device for measuring 
maximum values, where the driver may not drive the maximum indicator directly.  
For special design electricity meters, the accuracy tests must be performed under the following 
conditions:  
 electricity meter with multiple referenc e voltages: for electricity meters with multiple reference 
voltages or with the full range of reference voltages, the test is performed at the maximum and 
minimum voltages specified on the label;  
 electricity meters with two base currents: the test is perfo rmed at the lowest test point, at the 
smaller base current.At all other test points, the test is performed at the higher base current;  
 electricity meters with a data interface: instead of reading data visually, a device may be used to 
read the contents of the appropriate registers.However, the values read by the device and those 
indicated on the display must be identical (at least to the extent of the digits visible on the 
display).This comparison must be made at least once during the accuracy test;  
 transmi tting electricity meters: for meters equipped with terminals with a pulse output for remote 
energy measurement, in addition to the tests referred to above, this pulse output must be 
tested.The test station used must be equipped with an electronic device ca pable of receiving the 
type of pulses that are transmitted by the electricity meter.The test of the pulse output for remote 
measurement is performed at reference voltage, base current and unity power factor.  
 electricity meters with a maximum value meter ar e tested only on stations equipped for this 
measurement.The test is performed at reference voltage, base current and power factor  = 1.A 
measurement period of 15 minutes is used.Before starting the test, the 15 -minute maximum 
register is zeroed.The output r egister is read at the beginning and end of the measurement 
period.The error of the maximum output measured during the measurement period must be less 
than the maximum permissible errors in Tables  1 to 6.The test must be performed for active and 
reactive e nergy, both for demand and supply.  General Measure No  0111 -OOP -C022 -18 
31 7.6.4    Assessment of the accuracy test  
The electricity meter passes the test if the meter’s measurement errors are less than the error limits given 
in Tables  25 to 31 (the measurement uncertainty of the test equipment is  not taken into consideration 
when establishing meter error).  
Table  25 – Error limits for single -phase electromechanical and static active energy meters of 
accuracy class 0.5, 1 and 2 (also applies to electricity meters bearing the EEC mark)  
Measurement 
number  Current  cos φ Accuracy class for direct 
connected meters  Accuracy class for transformer 
operated meters  
0.5 1 2 0.5 1 2 
1 1) 5 (10) % Ib 1 ±1.0 % ±1.5 % ±2.5 % ±1.0 % ±1.5 % ±2.5 % 
2 100 % Ib 1 ±0.5 % ±1.0 % ±2.0 % ±0.5 % ±1.0 % ±2.0 % 
3 100 % Ib 0.5 ind.  ±0.8 % ±1.0 % ±2.0 % ±0.8 % ±1.0 % ±2.0 % 
4 Imax. 1 ±0.5 % ±1.0 % ±2.0 % ±0.5 % ±1.0 % ±2.0 % 
)   The value of current in the brackets apply to electromechanical electricity meters manufactured before the 
end of 1993.  
Table  26 – Error  limits for three -phase electromechanical and static active energy meters of 
accuracy class  0.5, 1 and 2 (also applies to electricity meters bearing the EEC mark)  
Measurement 
number  Current  Current 
in phases  cos φ Accuracy class for 
direct connected 
meters  Accuracy class for transformer 
operated meters  
1 2 0.5 1) 1 and 
1 S 2 
1 2) 5 (10)  % 
Ib L1-L2-L3 1 ±1.5 % ±2.5 % ±1.0 % ±1.5 % ±2.5 % 
2 50 % Ib L1 1 ±2.0 % ±3.0 % ±1.5 % ±2.0 % ±3.0 % 
3 3) 50 % Ib L2 1 ±2.0 % ±3.0 % ±1.5 % ±2.0 % ±3.0 % 
4 50 % Ib L3 1 ±2.0 % ±3.0 % ±1.5 % ±2.0 % ±3.0 % 
5 50 % Ib L1 0.5 ind.  – – ±1.5 % ±2.0 % – 
6 3) 50 % Ib L2 0.5 
ind. – – ±1.5 % ±2.0 % – 
7 50 % Ib L3 0.5 
ind. – – ±1.5 % ±2.0 % – 
8 100 % Ib L1-L2-L3 1 ±1.0 % ±2.0 % ±0.5 % ±1.0 % ±2.0 % 
9 100 % Ib L1-L2-L3 0.5 ind. ±1.0 % ±2.0 % ±0.8 % ±1.0 % ±2.0 % 
10 Imax. L1-L2-L3 1 ±1.0 % ±2.0 % ±0.5 % ±1.0 % ±2.0 % 
1)   Accuracy class 0.5 applies only to electromechanical electricity meters.  
2)   The value of current in the brackets apply to electromechanical electricity meters manufactured before the 
end of 1993.  
3)   Measurements no  3 and 6 are omitted for three -wire electricity meters.  
Table  27 – Error limits for three -phase static active energy meters of accuracy class 0.2  S and 
0.5 S 
Measurement 
number  Current  Current 
in phases  cos φ Accuracy class for 
direct connected 
meters  Accuracy class for transformer 
operated meters  
0.5 S 0.2 S 0.5 S 
1 2 % Ib L1-L2-L3 1 – ±0.4 % ±1.0 % 
2 5 % Ib L1-L2-L3 1 ±0.5 % ±0.2 % ±0.5 % General Measure No  0111 -OOP -C022 -18 
32 3 5 % Ib L1-L2-L3 0.5 ind.  ±1.0 % ±0.5 % ±1.0 % 
4 5 % Ib L1-L2-L3 0.8 cap.  ±1.0 % ±0.5 % ±1.0 % 
5 5 % Ib L1 1 ±0.6 % ±0.3 % ±0.6 % 
6 1) 5 % Ib L2 1 ±0.6 % ±0.3 % ±0.6 % 
7 5 % Ib L3 1 ±0.6 % ±0.3 % ±0.6 % 
8 10 % Ib L1-L2-L3 1 ±0.5 % ±0.2 % ±0.5 % 
9 50 % Ib L1 1 ±0.6 % ±0.3 % ±0.6 % 
10 1) 50 % Ib L2 1 ±0.6 % ±0.3 % ±0.6 % 
11 50 % Ib L3 1 ±0.6 % ±0.3 % ±0.6 % 
12 50 % Ib L1 0.5 ind.  – ±0.4 % ±1.0 % 
13 1) 50 % Ib L2 0.5 ind.  – ±0.4 % ±1.0 % 
14 50 % Ib L3 0.5 ind.  – ±0.4 % ±1.0 % 
15 100 % Ib L1-L2-L3 1 ±0.5 % ±0.2 % ±0.5 % 
16 100 % Ib L1-L2-L3 0.5 ind.  ±0.6 % ±0.3 % ±0.6 % 
17 100 % Ib L1-L2-L3 0.8 cap.  ±0.6 % ±0.3 % ±0.6 % 
18 Imax. L1-L2-L3 1 ±0.5 % ±0.2 % ±0.5 % 
1)   Measurements no  6, 10 and 13 are omitted for three -wire electricity meters.  
Table  28 – Error limits for single -phase electromechanical and static active energy meters of 
accuracy class A, B and C  
Measurement 
number  Current  cos φ Class A  Class B  Class C 1) 
1 Imin 1 ±2.5 % ±1.5 % ±1.0 % 
2 Itr 1 ±2.0 % ±1.0 % ±0.5 % 
3 Itr 0.5 ind.  ±2.0 % ±1.0 % ±0.5 % 
4 Iref 1 ±2.0 % ±1.0 % ±0.5 % 
5 Iref 0.5 ind.  ±2.0 % ±1.0 % ±0.5 % 
6 Iref 0.8 cap.  ±2.0 % ±1.0 % ±0.5 % 
7 Imax 1 ±2.0 % ±1.0 % ±0.5 % 
1)   Class C applies only to static electricity meters.  
NOTE  Itr = 10 % Iref for direct connected electricity meters;  
Itr = 5 % Infor transformer operated electricity meters.  
Table  29 – Error limits for three -phase electromechanical and static active energy meters of  
accuracy class A, B and C  
Measurement 
number  Current  cos φ Current in 
phases  Class A  Class B  Class C 1) 
1 Imin 1 L1-L2-L3 ±2.5 % ±1.5 % ±1.0 % 
2 Itr 1 L1-L2-L3 ±2.0 % ±1.0 % ±0.5 % 
3 Itr 0.5 ind.  L1-L2-L3 ±2.0 % ±1.0 % ±0.5 % 
4 50 % Iref 1 L1 ±3.0 % ±2.0 % ±1.0 % 
5 50 % Iref 1 L2 ±3.0 % ±2.0 % ±1.0 % 
6 50 % Iref 1 L3 ±3.0 % ±2.0 % ±1.0 % 
7 50 % Iref 0.5 ind.  L1 – ±2.0 % ±1.0 % 
8 50 % Iref 0.5 ind.  L2 – ±2.0 % ±1.0 % 
9 50 % Iref 0.5 ind.  L3 – ±2.0 % ±1.0 % 
10 Iref 1 L1-L2-L3 ±2.0 % ±1.0 % ±0.5 % 
11 Iref 0.5 ind.  L1-L2-L3 ±2.0 % ±1.0 % ±0.5 % 
12 Iref 0.8 cap.  L1-L2-L3 ±2.0 % ±1.0 % ±0.5 % 
13 Imax 1 L1-L2-L3 ±2.0 % ±1.0 % ±0.5 % 
1)   Class C applies only to static electricity meters.  General Measure No  0111 -OOP -C022 -18 
33 NOTE  Itr = 10 % Iref for direct connected electricity meters;  
Itr = 5 % Infor transformer operated electricity meters.  
Table  30 – Error limits for three -phase static reactive energy meters of accuracy class 0.5  S, 1 
and 1  S 
Measurement 
number  Current 
in phases  sin φ Value of current for electricity 
meters that are  Accuracy class  
direct connected  transformer 
operated  0.5 S 1 and 1  S 
1 L1-L2-L3 1 5 % Ib 2 % In ±1.0 % ±1.5 % 
2 L1-L2-L3 1 10 % Ib 5 % In ±0.5 % ±1.0 % 
3 L1-L2-L3 0.5 ind.  10 % Ib 5 % In ±1.0 % ±1.5 % 
4 L1-L2-L3 0.8 cap.  10 % Ib 5 % In ±1.0 % ±1.5 % 
5 L1 1 50 % Ib 50 % In ±0.7 % ±1.5 % 
6 1) L2 1 50 % Ib 50 % In ±0.7 % ±1.5 % 
7 L3 1 50 % Ib 50 % In ±0.7 % ±1.5 % 
8 L1-L2-L3 1 100 % Ib 100 % In ±0.5 % ±1.0 % 
9 L1-L2-L3 0.5 ind.  100 % Ib 100 % In ±0.5 % ±1.0 % 
10 L1-L2-L3 0.5 cap.  100 % Ib 100 % In ±0.5 % ±1.0 % 
11 L1-L2-L3 1 Imax Imax ±0.5 % ±1.0 % 
1) Measurement no  6 is omitted for three -wire electricity meters.  
Table  31 – Error limits for three -phase static reactive energy meters of accuracy class 2 and 3  
Measurement 
number  Current in 
phases  sin φ Value of current for electricity 
meters that are  Error limit  
direct 
connected  transformer 
operated  2 3 
1 L1-L2-L3 1 5 % Ib 2 % In ±2.5 % ±4.0 % 
2 L1-L2-L3 1 10 % Ib 5 % In ±2.0 % ±3.0 % 
3 L1-L2-L3 0.5 ind.  10 % Ib 5 % In ±2.5 % ±4.0 % 
4 L1-L2-L3 0.8 cap.  - 5 % In ±2.0 % ±3.0 % 
5 L1 1 50 % Ib 50 % In ±3.0 % ±4.0 % 
6 1) L2 1 50 % Ib 50 % In ±3.0 % ±4.0 % 
7 L3 1 50 % Ib 50 % In ±3.0 % ±4.0 % 
8 L1-L2-L3 1 100 % Ib 100 % In ±2.0 % ±3.0 % 
9 L1-L2-L3 0.5 ind.  100 % Ib 100 % In ±2.0 % ±3.0 % 
10 L1-L2-L3 0.8 cap.  100 % Ib 100 % In ±2.0 % ±3.0 % 
11 L1-L2-L3 1 Imax Imax ±2.0 % ±3.0 % 
1) Measurement no  6 is omitted for three -wire electricity meters.  
7.7   Counter test  
The counter test is performed only if the accuracy test was performed  according to Article  7.6.1, 
paragraph (a), using the method of recording rotor revolutions or pulses from the tested electricity meter.  
The counter test is performed at power factor  = 1 and at a single current between the base and maximum 
currents.  
NOTE    If maximum current Imax is not indicated on the label of the electricity meter, for the purposes of this 
regulation, it is equal to 1.2 times the nominal (base) current indicated on the label.  
The electricity meter passes the test if the observed differen ce between the error when using the method 
of recording rotor revolutions or pulses from the tested electricity meter and that when using the method 
of reading data on the counter of the tested meter at the same current is less than 1/10 of the error limit  General Measure No  0111 -OOP -C022 -18 
34 at reference conditions.In the case of electricity meters with a mechanical counter, this ratio is increased 
to 1/4 of the error limit.  
In the case of electricity meters of accuracy class 0.2  S, this ratio is increased to 1/4 of the error limit.  
7.8   Subsequent verification of electricity meters using the statistical sampling test  
For subsequent verification of electricity meters installed in the distribution grid, a statistical sampling 
test of a specified lot of electricity meters may be performed upon request.  
7.8.1    Lot for a statistical sampling test  
The lot may only comprise electricity meters from a single manufacturer that are of the same type and 
have the same reference voltage and reference and maximum currents.Once created, this lot may not be 
changed and the included electricity meters may not be included in another lot for another subsequent 
verification using the statistical sampling test.  
The most recent valid verification of the electricity meters in the lot or conformity assessment of the 
electricity meters in the lot when put into use must have been performed at a time interval no longer 
than two consecutive years.  
7.8.2    Statistical method used  
The statistical sampling test may be performed by making one or two selections from the lot of  the 
electricity meters according to recognised statistical methods.The selection made may include a 
specified lot of substitute electricity meters to be added to the tested sample during the tests.  
Logistical and other details of performing the statistica l sampling test, including sampling plans, are 
specified in an internal regulation of the metrological body performing the verification.  
7.8.3    Tests to be performed  
All electricity meters in the submitted sample are subjected to the full tests prescribed  for subsequent 
verification of electricity meters under Articles  7.2 and 7.4 to 7.7.If an electricity meter from the sample 
fails to pass the visual inspection referred to in Article  7.2, it may be substituted by an electricity meter 
from the lot of subst itute meters.  
An electricity meter is classified as non -complaint if it does not pass the no -load condition test referred 
to in Article  7.4 and the start -up test referred to in Article  7.5, and if the error established during the 
accuracy test referred to in Article  7.6 is greater than the error limits given for the individual types of 
meters in Tables  25 to 31.  
7.8.4    Assessment of the results of the statistical sampling test  
The control sample of electricity meters is assessed as compliant if the accepta nce requirements under 
the sampling plan for the selective check agreed to in advance have been met.Otherwise, the result is 
‘non-compliant’.  
If the result of the selective check is ‘non -compliant’, all electricity meters in the lot are assessed as non-
compliant.  
8   Measuring instrument examination  
When examining measuring instruments pursuant to §  11a of the Metrology Act at the request of a 
person who may be affected by incorrect measurement, all the relevant tests under Chapter  7 that are 
technic ally feasible will be performed; the last sentence of Article  7.2 does not apply.  General Measure No  0111 -OOP -C022 -18 
35 The maximum permissible error applied will be double the maximum permissible errors given for the 
individual types of electricity meters in Tables  25 to 31.The requirements f or start -up, no -load operation 
and the counter remain unchanged when carrying out this examination.  
9   Notified standards  
For the purposes of specifying the metrological and technical requirements for measuring instruments 
and specifying the testing metho ds for their type approval and verification arising from this general 
measure, the CMI must notify Czech technical standards, other technical standards or technical 
documents of international or foreign organisations, or other technical documents containin g more 
detailed technical requirements (hereinafter ‘notified standards’).The CMI shall publish a list of these 
notified standards attached to the relevant measures, together with the general measure, in a manner 
accessible to the public (at www.cmi.cz ). 
Compliance with notified standards or parts thereof is considered, to the extent and under the conditions 
stipulated by a general measure, to be compliance with the requirements stipulated by this measure to 
which these  standards or parts thereof apply.  
Compliance with notified standards is one way of demonstrating compliance with the 
requirements.These requirements may also be met by using another technical solution guaranteeing an 
equivalent or higher level of protecti on of legitimate interests.  
II. 
G R O U N D S 
The CMI has issued this general measure laying down metrological and technical requirements for 
legally controlled measuring instruments and tests for the type approval and verification of legally 
controlled me asuring instruments – ‘electricity meters’ – in accordance with §  14(1)(j) of the Metrology 
Act to implement §  6(2), §  9(1) and (9), and §  11a(3) of the Metrology Act.  
Under items 4.1.1, 4.1.2 and 4.1.3 in the Annex ‘List of the Types of Legally Controlled  Measuring 
Instruments’ to Implementing Decree No  345/2002 specifying the measuring instruments whose 
verification is mandatory and measuring instruments subject to type approval, as amended, this type of 
measuring instruments is classified as instruments subject to type approval and mandatory verification.  
This legislation (general measure) will be notified in accordance with Directive (EU) 2015/1535 of the 
European Parliament and of the Council of 9  September  2015 laying down a procedure for the provision  
of information in the field of technical regulations and of rules on Information Society services.  
III. 
I N S T R U C T I O N S 
In accordance with §  172(1) APC, in conjunction with §  39(1) APC, the CMI has stipulated a time limit 
for comments of 30  days from the date of posting the draft on the official notice board.Comments 
submitted after this time limit will not be considered.  
The persons concerned are hereby invited to comment on this draft general measure.With a view to the 
provisions of §  172(4) APC , the comments are to be submitted in writing.  
Pursuant to the provisions of §  174(1) APC, in conjunction with the provisions of §  37(1) APC, it must 
be clearly stated who is submitting the comments, which general measure the comments concern, how 
the draf t contradicts legislation or how the general measure is inaccurate. The comments must also 
contain the signature of the person making the comments.  
The supporting documents for this draft general measure may be consulted at the Czech Metrology 
Institute, L egal Metrology Department, Okružní 31, 638 00 Brno, after making arrangements by 
telephone.  General Measure No  0111 -OOP -C022 -18 
36 This draft general measure shall be posted for 15  days.  
 
 
 
 ................................ .......................   
RNDr.Pavel Klenovský m.p.  
Director General  
 
Person responsible for accuracy:Mgr.Tomáš Hendrych  
Posted o n:1 June 2018   
Signature of the authorised person confirming 
posting:  Mgr.Tomáš Hendrych m.p.  
  
Removed on:   
Signature of the authorised person confirming 
removal: