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GUIDELINE FORELECTRICITY METERS:APPROVAL, TESTING AND INITIAL

VERIFICATION REQUIREMENTS

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DOCUMENT CONTROL

Revision number Date Review by Justification for reviewDraft 01/2012 28 August 2012 Approved by Energy

CommissionRevision 01-2013 7 March 2013 Working Group Metering

Guideline & JabatanStandard Malaysia

Ratifying for existingprocess

Revision 02-2013 28 April 2013 ST & SIRIM QAS To include additionalrequirement forimported meter

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CONTENTS

PART 1: PRELIMINARY 3

PART 2: APPROVAL REQUIREMENT 6

PART 3: TESTING & INITIAL VERIFICATION 12

PART 4: GENERAL 14

FIRST SCHEDULE: METROLOGICAL REQUIREMENT 15

SECOND SCHEDULE: INITIAL VERIFICATION PROCEDURE

Annex 1

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PART 1

PRELIMINARY

Interpretation

1. In these Guidelines, unless the context otherwise requires:

“Act” means Electricity Supply Act 1990.

“Accredited Laboratory” means a testing facility accredited to MS ISO/IEC 17025 general

requirements for the competence of testing and calibration laboratories or other laboratory

recognised by national accreditation and standardisation authority.

“Accredited Certification Bodies” means accredited by Standards Malaysia

“Accreditation and Standardisation Authority” means Department of Standards Malaysia

“Applicant” means any company who is supplied electricity meter to licensee used for the

sale of electricity

“Authorised Manufacturer” means any company who manufactures electricity meters which

complies with these guidelines and operates a quality management system which conforms

to MS ISO 9001 or equivalent.

“Batch Certification” means conformity assessment requirement for imported meters

through consignment or batch testing

“Certificate of Approval” means approved document issued by Commission (In line with

regulation 97 of Electricity Regulation 1994)

“Certificate of Pattern Approval” means approved document issued by National

Measurement Standard Laboratory

“Commission” means Energy Commission, Malaysia.

“Consumer” means as prescribed in the Act

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“Electricity Meter” means self contained measuring instrument intended to measure

electrical energy continuously by integrating power with respect to time and to store the

result

“International Recognised Laboratory” means an international testing and calibration

laboratory which is accredited by recognised international accreditation and standardization

body which signatory to Asia Pacific Laboratory Accreditation Cooperation (APLAC) or

International Laboratory Accreditation Cooperation (ILAC), Mutual Recognition Arrangement

(MRA)

“Licensee” means as prescribed in the Act

“National Measurement Standards Laboratory” means National Metrology Laboratory

(NML), SIRIM Berhad

“Pattern Approval” means a meter type which has been evaluated and approved by a

National Measurement Standards Laboratory through compliance with International

Organization of Legal Metrology (OIML) standards, and by then issued a Certificate of Pattern

Approval

“Product Certification” means a conformity assessment system operated by Accredited

Certification Bodies related to product to which the same product certification requirements,

specified standard and procedure including relevant regulatory provisions apply

“Product Certification License” means a document issued by Accredited Certification Bodies

recording the conformance of a product to the specified standard(s) and the Accredited

Certification Bodies certification requirements in accordance to the product certification

agreement

“Reference Standard” means electricity measurement standard which traceable to national

standards by periodic calibration interval National Measurement Standards Laboratory

“Testing facility” means a combination of meter test bench and working standards, used for

the testing and verification of electricity meters

“Transfer Standard” means a Standard that has been verified by comparison to a Reference

Standard and is used to compare Working Standards indirectly against Reference Standards

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“Type Test Report” means a full type test report issued by an independent accredited test

laboratory recognised by accredited certification bodies

“Working Standard” means a standard that has been verified by comparison to a Reference

Standard or to a Transfer Standard and is used for testing and verification of electricity

meters. Test equipment used for onsite testing and dispute resolution is deemed ‘Working

Standards’

“Year” means calendar year, according to the Gregorian calendar

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PART 2

APPROVAL REQUIREMENT

Obligation of Parties to Ensure Fairness

2. The sale of electricity through electricity meters shall be subjected to practices that

ensure fairness and equity for both the customer and the supplier. Both parties must

understand their rights and responsibilities. Meters and their installation must be practical

and where appropriate, consistent with international standards.

Regulatory Requirement on Electricity Meters

3. (1) In ensuring all meters when manufacture are in compliance with the regulatory

requirement, reference to Annex 1 stipulate the overall regulatory requirements that need to

be complied with by manufacturer for the electricity meter before it can be installed at any

premises.

(2) With a view to use for trade, the pattern or design of electricity meters shall be

approved by National Measurement Standard Laboratory.

(3) All electricity meters used for billing purposes by a licensee must be certified by

Accredited Certification Bodies to show that, when tested, they conformed to the original

pattern approval and operated within the prescribed levels of accuracy.

(4) The licensee shall be supplied with appropriate documentation to certify that all

meters are manufactured and individually tested in accordance with MS Standards, where the

standards states it is applicable to newly manufactured electricity meters and the

requirements of this guideline.

Appropriate Meter

4. For the purpose of subsection (32) (1) of the Act, a meter is appropriate if it complies

with the following requirements;

(a) MS 62053-11: Electromechanical meters for active energy (classes 0.5, 1 and

2);

(b) MS 62053-21: Static Meters for active energy (classes 1 and 2);

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(c) MS 62053-22: Static Meters for active energy (classes 0.2S and 0.5S);

(d) MS 62053-23: Static Meters for reactive energy (classes 2 and 3);

(e) MS 62052-11: Electricity metering equipment (AC) – General requirements,

tests and test conditions, Part 11: Metering equipment;

(f) First Schedule of this Guideline ; and

(g) Metering Code as specified in the Malaysian Distribution Code.

Pattern Approval

5. (1) Before any electricity meters can be manufactured, the authorised manufacturer

shall apply to the National Measurement Standards Laboratory for Pattern Approval, where

such approval may include metrological performance and maintaining calibration in the

range of operating conditions that is stated in this guideline.

(2) The process for Pattern Approval includes an assessment of the prototype of theelectric meter to ensure that they meet the required standards. Type Test Report of theproduct shall be included.

(3) Once approved, a Certificate of Pattern Approval will be issued by NationalMeasurement Standards Laboratory. Evaluation report and recommendation for new PatternApproval will then issued by National Measurement Standards Laboratory.

(4) Any changes to the pattern found during Product Certification audit, shall bereported to National Measurement Standards Laboratory and Commission.

Certificate of Approval (COA)

6. (1) The authorised manufacturer shall apply to Commission for new meter to haveCertificate of Approval (COA).

(2) The application shall be done with online application through e-Permit. Type TestReport shall be included and Commission will verify the validity and authenticity of the report.

(3) Once approved, a Certificate of Approval will be issued by Commission and must berenew every year.

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Product Certification

7. (1) Accredited Certification Bodies, with the participation of the Commission wherenecessary, will carry out preliminary examination and evaluation of manufacturing productionof electricity meters.

(2) Authorised manufacturer shall submit the Certificate of Pattern Approval,Certificate of Approval and Type Test Report during application to Accredited CertificationBodies.

(3) Accredited Certification Bodies will evaluate the Type Test Report in whichreferring to stipulated requirements and international standards. The validity of Type TestReport is not more than 10 years and for new application, the validity period must not lessthan one year.

(4) Pre-requisite for the audit, authorised manufacturer shall have AccreditedLaboratory.

(5) Accredited Certification Bodies will perform the audit on the production ofelectricity meters to ensure that the quality system and product conform to the stipulatedrequirements and standard. Verification test may be conducted using in depth surveillancemethod according to accredited test laboratory practices.

(6) Examination of the facts from the verification tests will be documented in the testreport that will determine the basis for the certification of the product.

(7) Only authorised manufacturer with electricity meters that complies with productcertification processes and received a valid Certificate of Approval by the Commission willhave the right to affix the Accredited Certification Bodies certification mark or label onelectricity meters.

(8) Surveillance audit by Accreditation Certified Bodies with the participation ofCommission where necessary will be performed every year.

(9) Where non-conformity or defects identified in the production process or during

the auditing process control of the electricity meters, Accredited Certification Bodies will

require the manufacturers to do corrective action within a reasonable period of time.

Accredited Certification Bodies will confirm satisfactory action has been implemented by the

Authorised Manufacturer before issuing the product certification license.

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(10) If the action taken is not satisfactory or if additional testing fails to meet specifiedcriteria, the Accreditation Certified Bodies in consultation with the Commission shall issue anotice of suspension of production to the manufacturer.

(11) If a Certificate of Approval has been issued, the Commission has the right to

revoke or suspend it under the following circumstances:

i) if the Authorised Manufacturer has fail to maintain its quality control such that

the electricity meters installed in the consumers’ premises are found to be of

non-compliance to the requirement of this guideline;

ii) if the Authorised Manufacturer is found to have made false declaration or

giving misleading information;

iii) if the Authorised Manufacturer ceases its operation or in the process of winding

up;

iv) if there is a Court order to the effect of preventing the use of such meter;

v) if the usage of the particular meter can pose danger to the consumer;

vi) any other circumstances that the Commission feels reasonable to suspend or

revoke in view of public interest.

(12) Once the Certificate of Approval is suspended or revoked, the manufactureris notpermitted tousethe Accredited Certification Bodies certification mark or labels on electricitymeters.

(13) The Authorised Manufacturer shall be required to comply with the AccreditedCertification Bodies procedures with regards to suspension, revocation, withdrawal andtermination of product certification license.

Batch Certification

8. (1) Every imported electricity meters shall be verified through the batch certificationprocedure, performed by Accredited Certification Bodies.

(2) Applicant shall submit application to Accredited Certification Bodies with completedocumentation. Document required as mentioned in sub-requirement 7 (2).

(3) The evaluation of document by applicant as mentioned in sub-requirement 7 (3).

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(4) The consignment test shall be performed by sampling method. Approval is givenonly to consignments which have satisfactorily gone through the inspection and testingprocess.

(5) Only applicant with electricity meters that complies with batch certificationprocesses and received a valid Certificate of Approval by the Commission will have the rightto affix the Accredited Certification Bodies certification mark or label on electricity meters.

Markings

9. (1) The electricity meter shall be legibly & durably marked as a minimum with the

followings:

a) Manufacturer

b) Vnom

c) Imax

d) fnom

e) Ib / In

f) Serial number

g) Number of phases

h) Number of wires

i) Meter constant (s)

j) Year of manufacture

k) Accuracy class

l) Directionality of energy flow if the meter is bidirectional or unidirectional. No

marking is required if the meter is capable only of positive direction of positive

direction energy flow

m) Meter type

n) The connection mode (s) for which the meter is specified

o) Connection terminals uniquely identified to distinguish between terminals

p) “Product Certification” mark or labels approved by Commission

(2) The marking on the meters shall be indelible, distinct and legible from outside the

meter. The markings of electricity meter intended for outdoor locations shall withstand solar

radiation. If the serial number is affixed to dismountable parts, the serial number shall also be

provided in a position where it is not readily dissociated from parts determining the

metrological characteristics.

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(3) Electricity meters shall be provided with suitable means of sealing metrological

sensitive parts. A seal is used to provide security for the electricity meter from tampering and

it can be in the form of a crimped security seal or any suitable form.

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PART 3

TESTING & INITIAL VERIFICATION

Initial verification

10. (1) Every electricity meter shall be tested and calibrated with the applicable

standard(s) by Authorised Manufacturer with an Accredited Laboratory.

(2) Initial verification process shall be performed in the manner as stipulated in Second

Schedule of this guideline or in such manner as determine by the Commission in consultation

with National Measurement Standards Laboratory.

(3) Each meter shall display the year it was last tested and verifed.

(4) Once verified, a meter may remain in service for a period of 10 years of any suchperiod as approved by the Commission, except where the meter is suspected to bemalfunctioning.

(5) Each meter type shall have ascribed to it a certification life (time to allow oncircuit). If no supporting evidence is available, a period of 10 years or such time that themeter to operate within permitted margins of error, whichever is least. In any event no metershall remain on circuit for periods exceeding 20 years.

Records

11. (1) The licensee shall maintain auditable records of all meters on circuit and theirprojected date of replacement. The minimum retention period for the records is 10 years.

(2) The following records shall be kept and made available for inspection by theCommission or its representative at any time;

(a) Test certificate of all in service electricity meters,(b) Meter test equipment / standards calibration history,(c) Meter re-certification or replacement schedules,(d) Result of all ad hoc on site or laboratory meter testing initiated by the

customer or licensee,(e) For every account, details of the meter (s) installed.

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Meter testing equipment

10. (1) The following pieces of test equipment are deemed by this guideline to beStandards;

(a) Reference standards,(b) AC/DC Transfer standards,(c) AC transfer standard,(d) Working standards.

(2) All Standards shall be maintained and calibration at the following intervals by anapproved accredited laboratory and/or National Measurement Standards Laboratory;

Standard type Maximum period between calibrations

Reference Standards 2 year

AC/DC Transfer Standards 1 year

AC Transfer Standards 1 year

Working Standards 1 year

(3) Test reports provided by approved accredited laboratories, shall be retained for

inspection on request by the Commission

(4) Apparatus used for the regulating and testing of electricity meters shall cease to be

used if periodic verification shows the instrument to be inaccurate or unstable. Such

apparatus must not be brought back into service until it has been repaired and re-calibrated.

(5) For any test load, the load applied to a working standard integrating meter shall

not be less than 25% or more than 125% of its full load rating. For a working standard, the

applied load shall not be less than 40 per cent or more than 100% of its full scale or range

reading.

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PART 4

GENERAL

Public information

11. (1) The licensee shall provide metering information as public handouts available from

their offices and other suitable facilities. These include, but not limited to the following

advice;

a) How to read a meter,

b) Customer obligations on meter care,

c) What to do if you think your bill is too high,

d) Advice who to contact with queries,

e) How to get meter checked,

f) Dispute resolution procedure,

(2) Once metered consumption has commenced the licensee is responsible for

maintenance and replacement of the meter. However both the licensee and consumer

shall have obligations in keeping electricity meter in good order, and these obligations

should be emphasized in published documentation.

Transition

12. (1) The licensee, in implementing this guideline shall produce a transition plan to

ensure that all metering procedures are in compliance by nominated future dates.

(2) The plan, which shall be provided to the Commission, shall include but not be

limited to;

a) Phasing out of non compliance meters,

b) Meter replacement programs which take account of failure rates,

c) Production of Public Information,

d) Procurement of meters only in compliance with this regulation,

e) Upgrading of Test & Calibration facilities,

f) Implementation and phasing of 100% customer metering for electricity;

g) Phasing out of meters older than 20 years.

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FIRST SCHEDULE

METROLOGICAL REQUIREMENTS

1.0 Metrological characteristics

1.1 Current (I)

R.M.S value of the electrical current flowing through the electricity meter

1.2 Starting current (Ist)

Lowest value of current specified by the manufacturer at which the electricity meter should

register electrical energy at unity power factor and, for poly-phase electricity meters, with

balanced load

1.3 Minimum current (Imin)

Lowest value of current at which the electricity meter is specified by the manufacturer to

meet the accuracy requirement by this guideline

1.4 Basic current (Ib)

Value of current in accordance with the relevant performance of a direct connected electricity

meter are fixed

1.5 Rated current (In)

Value of current in accordance with the relevant performance of a transformer operated

electricity meter are fixed

1.6 Transitional current (Itr)

Value of current at and above which the electricity meter is specified by the manufacturer to

lie within smallest maximum permissible error corresponding to the accuracy class of the

electricity meter

1.7 Maximum current (Imax)

Highest value of current at which the electricity meter is specified by the manufacturer to

meet the accuracy requirements of this guideline

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1.18 Active energy

Active power integrated over time. Usually expressed in kWh or MWh

T T

E(T ) = ∫p(t) ⋅dt = ∫u(t) ⋅ i(t) ⋅dt

0 0

where:

E is the active energy. Other symbols are as defined in Active power definition

1.19 Relative error (of indication)

Measured quantity value minus reference quantity value, divided by the reference quantity

value. The relative error is usually expressed as a percentage of the reference quantity

value.

1.20 Maximum permissible error (m.p.e)

Extreme value of a measurement error, with respect to a known reference quantity value,

permitted by specifications or regulations for a given electricity meter. (measurement,

measuring instrument, or measuring system)

1.21 Base maximum permissible error

Extreme values of the error (of indication) of a meter, when the current and power factor

are varied within the intervals given by the rated operating conditions, and when the meter

is otherwise operated at reference conditions.

1.22 Maximum permissible error shift

Extreme values of the change in error (of a meter, permitted by this guideline, when a

single influence factor is taken from its value at reference conditions and varied within

the rated operating conditions. For each influence factor there is one corresponding

maximum permissible error shift.

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1.23 Rated operating condition

Operating conditions that must be fulfilled during measurement in order that an electricity

meter performs as designed

1.24 Reference condition

Operating conditions prescribed for evaluating the performance of an electricity meter for

comparison of measurement results

1.25 Accuracy class

Class of measuring instruments or measuring systems that stated metrological requirements

that are intended to keep measurement errors or instrumental uncertainties within specified

limits under specified operating conditions

1.26 Durability

Ability of a measuring instrument to maintain its performance characteristics over a period of

use

1.27 Measurand

The particular quantity subject to measurement

2.0 Metrological requirements

2.1 Units of measurement

The units of measurement for active electrical energy shall be one of the following units:

Wh, kWh, MWh, GWh

2.2 Rated operating conditions

Rated operating conditions are specified in Table 1.

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Table 1: Rated operating conditions

Conditions or

influence quantity

Values, Ranges

Frequency fnom ±2% where fnom is to be specified by the manufacturer.

If the manufacturer specifies more than one nominal frequency, the

rated operating conditions shall be the combination of all fnom ±2%

intervals

Voltage Unom ±10% where Unom is to be specified by the manufacturer.

Meters designed to operate across a range of voltages shall have

applicable Unom ‘s specified by the manufacturer. If the manufacturer

specifies more than one nominal voltage the rated operating conditions

shall be the combination of all Unom ±10% intervals

Current Ist to Imax

Imax, Itr, Imin and Ist are to be specified by the manufacturer in

accordance with the following:

Direct

Connected

Accuracy Class

2 1 0.5 0.2

Imax / Itr ≥ 50 ≥ 50 ≥ 50 ≥ 50

Imax / Imin ≥ 100 ≥ 125 ≥ 250 ≥ 250

Imax / Ist ≥ 1000 ≥ 1250 ≥ 1250 ≥ 1250

Transformer

operated

Accuracy Class

2 1 0.5 0.2

Imax / Itr ≥ 24 ≥ 24 ≥ 24 ≥ 24

Imax / Imin ≥ 60 ≥ 100 (1) ≥ 100 ≥ 100

Imax / Ist ≥ 480 ≥ 600 ≥ 1200 ≥ 1200

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Power factor From 0.5 inductive to 1 to 0.8 capacitive, except for classes 0.5 and 0.2

where the operating range is from 0.5 inductive to 1 to 0.5 capacitive.

For bi-directional meters the power factor range limits are valid in both

directions.

Temperature As pre-scribed in MS 62052-11:2009

Humidity and

water

As pre-scribed in MS 62052-11:2009

Connections modes The manufacturer shall specify whether the meter is intended for

direct connection, connection through current transformers or

through current and voltage transformers.

The manufacturer shall specify the connection mode(s), the number

of measurement elements of the meter and the number of phases of

the electric system for which the meter is intended.

A meter in accordance with this recommendation can be (but is not

limited to) one or more of the following:

Description

Single-phase two wire, 1 element

Three-phase four wire 3 element

Three-phase three-wire 2-element (applicable only in cases where

leakage currents can be ruled out)

The manufacturer may specify alternative connection modes for

poly-phase meters. These alternative connection mode(s) shall also

be part(s) of the operating conditions.

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Harmonics The voltage and current shall be allowed to deviate from the

sinusoidal form.

Load balance The load balance shall be allowed to vary from fully balanced

conditions to current in only one current circuit for poly-phase

meters.

2.3 Accuracy requirements

2.3.1 General

a) The manufacturer shall specify the accuracy class of the electricity meter to be one of

class: 2, 1, 0.5 or 0.2

b) The electricity shall be designed and manufactured such that its error does not exceed

the maximum permissible error for the specified class under rated operating

conditions

c) The meter shall be designed and manufactured such that, when exposed to

disturbances, significant faults do not occur

Note: Type and accuracy of electricity meter consumption as prescribed in Malaysia

Distribution Code; Clause 9.5.3: Type and Accuracy of Revenue Metering Equipment

2.3.2 Direction of energy flow

Where a manufacturer has specified that a meter shall be capable of bidirectional

energy flow, the electricity meter shall correctly handle both positive and negative mean

energy flow and the electricity meter shall fulfill the requirement of this guideline for energy

flow in both directions. The polarity of energy flow shall be defined by the manufacturer’s

connection instructions for the meter. Mean energy flow refers to the active power

integrated over at least one cycle of the nominal frequency.

A meter shall fall into at least one of the following categories:

Single-register, bi-directional; where the meter is specified as capable of measuring

both positive and negative mean energy flow, and where the net result will be placed

in a single register.

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Two-register, bi-directional: where the meter is specified as capable of measuring

both positive and negative mean energy flow, as defined by connection of the meter,

and where the positive result and negative result are placed in different registers.

Single-register, positive direction only; where the meter is specified as capable of

measuring and registering only positive mean energy flow. It may inherently, by its

design, register only positive mean energy flow or it may be equipped with reverse

running detent.

Single-register, uni-directional; where the meter is specified as capable of measuring

and registering the absolute value of the mean energy flow. Normally such a meter

will register all energy as consumed energy independent of the true direction of the

energy flow or of how the meter is connected.

For bi-directional meters, energy registration shall occur in the correct register when the

direction of flow changes.

Note: The terms “single-register” and “two register” in the list above refer to the basic

energy register(s) only. A meter may have other registers, e.g. for storage of tariff and/or

phase information.

2.3.3 Base maximum permissible errors

The intrinsic error (expressed in percent) shall be within the base maximum permissible

error stated in Table 2 when the current and power factor are varied within the limits

given by Table 2 (operating range), and when the meter is otherwise operated at

reference conditions.

Table 2: Base maximum permissible errors and no load requirements

Quantity Base maximum permissible errors (%) for meters of class

Current (I) Power factor 2 1 0.5 0.2

Itr ≤ I ≤ Imax

Unity ± 2.0 ± 1.0 ± 0.5 ± 0.2

0.5 inductive to 1 to 0.8

capacitive

± 2.5 ± 1.5 ± 0.6 ± 0.3

Imin ≤ I < Itr

Unity ± 2.5 ± 1.5 ± 1.0 ± 0.4

0.5 inductive to 1 to 0.8

capacitive

± 2.5 ± 1.8 ± 1.0 ± 0.5

Ist ≤ I < Imin Unity ± 2.5*Imin / I ± 1.5*Imin / I ± 1.0*Imin / I ± 0.4 *Imin /I

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2.3.4 No load

No significant energy shall be registered under conditions of no load. The meter is always

allowed to stop for currents below Ist

2.3.5 Allowed effects of influence quantities

The temperature coefficient of the meter shall fulfill the requirement of Table 3 when the

meter is otherwise operated at reference conditions.

Table 3: Limits for temperature coefficient of error

Influence quantity Power

factor

Limits for temperature coefficient

(%K) for meters of class

2 1 0.5 0.2

Temperature Coefficient (%K), over any

interval, within the temperature range,

which is not less than 15K and not greater

than 23K, for current

Itr ≤ I ≤ Imax

1± 0.1 ± 0.05 ± 0.03 ± 0.01

0.5

inductive± 0.15 ± 0.07 ± 0.05 ± 0.02

2.4 Protection against corruption

a) The metrological characteristics of the electricity meter shall not be influenced in any

inadmissible way by the connection to it of another device, by any feature of the

connected device itself or by any remote device that communicates with the

electricity meter

b) A hardware component that is critical for metrological characteristics shall be

designed so that it can be secured. Security measures foreseen shall provide for

evidence of an intervention

c) Software that is critical for metrological characteristics shall be identified as such and

shall be secured

d) Software identification shall be easily provided by the electricity meter

e) Evidence of a software intervention shall be available for a reasonable period of time

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f) Measurement data, software that is critical for measurement characteristics and

metrologically important parameters stored or transmitted shall be adequately

protected against accidental or intentional corruption

g) The display of the total quantity supplied or the displays from which the total quantity

supplied can be derived, whole or partial reference to which is the basis for payment,

shall not be able to be reset during use

2.5 Suitability for use

2.5.1 Readability of result

The meter shall have one (or more) indicating device (s) which is (are) capable of

presenting or displaying numerical value of each legal unit of measure for which the meter is

approved. The indicating device shall be easy to read and the characters of measurement

results shall as minimum be 4 mm high. Any decimal fractions shall be clearly indicated; for

mechanical registers, any decimal fraction drum shall be marked differently.

The indicating device shall not be significantly affected by exposure to normal

operating conditions over the maximum duration of the meter lifetime.

The indicating device shall be able to display all data relevant for billing purposes. In

the case of multiple values presented by a single indicating device it shall be possible to

display the content of all relevant memories. For automatic sequencing displays, each display

of register for billing purposes shall be retained for a minimum of 5 s.

For multi tariff meters, the register which reflects the active tariff shall be indicated. It

shall be possible to read each tariff register locally and each register shall clearly identify.

Electronic registers shall be non-volatile so that they retain stored values upon of

power. Stored values shall not be overwritten and shall be capable of being retrieved upon

restoration of power. The register shall be capable of storing and display an amount of energy

that corresponds to the meter running at P = Vnom x Imax x n for at least 4000 h, where n is the

number of phases. This capability for storage and display applies to all registers relevant for

billing including positive and negative flow registers for bi-directional meters and tariff

registers for multi tariff meters.

In the case of electronic registers, the minimum retention time for results is one year

for a disconnected meter. Electronic indicating devices shall be provided with a display test

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that switches all the display segments on then off for the purpose of determining whether all

display segments are working.

2.5.2 Testability

The meter shall be equipped with a test output for efficient testing, such as rotor with

a mark or a test pulse output. If the design of the test output is such that the pulse rate does

not correspond to the measured power in every given relevant time interval, the

manufacturer shall declare the necessary number of pulses to ensure a standard deviation of

measurement less than 0.1 base m.p.e, at Imax, Itr and Imin.

The relation between the measured energy given by the test output and the measured

energy given by the indicating device shall comply with the marking on the name plate.

The wavelength of the radiated signals for emitting systems shall be between 550 nm

and 1000 nm. The output device in the meter shall generate a signal with a radiation strength

ET over a defined reference surface (optically active area) at a distance of 10 mm ± 1 mm from

the surface of the meter, with the following limiting values:

ON condition : 50 µ W/cm2 ≤ ET ≤ 7500 µ W/cm2

OFF condition : ET ≤ 2 µ W/cm2

2.5.3 Durability

The meter shall be designed to maintain an adequate stability of its metrological

characteristics over a period of time specified by the manufacturer, provided that it is

properly installed, maintained and used according to the manufacturer’s instructions when in

the environmental conditions for which it is intended. The manufacturer shall provide

evidence to support the durability claim.

The meter shall be designed to reduce as far as possible the effect of a defect that

would lead to an inaccurate measurement result.

The meter shall be designed and manufactured such that either

a) Significant errors do not occur, or

b) Significant durability errors are detected and acted upon by means of a

durability protection.

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SECOND SCHEDULE

INITIAL VERIFICATION PROCESS

1.0 General

This schedule applies to the initial verification of electricity meters in use for trade

which have been either manufactured within or imported into Malaysia. This schedule does

not apply to the re-verification or in service testing or electricity meters.

2.0 Testing

2.1 Calibration status

Check that the test system used has sufficient accuracy to verify the meters under test, and

that the calibration is valid.

2.2 Conformity check

Check that the electricity meter is manufactured in conformity with the pattern approval

documentation

2.3 Warming up

It may be necessary to warm the meter up before full operation. The length of the warming

up period depends on the actual type of instrument and shall be determined in advance.

During the test for initial intrinsic error the electricity meter shall be allowed to stabilize at

each current level before measurements for a period, no longer than 5 minutes, to be

nominated by the manufacturer. The order of the testpoints shall be from lowest current to

highest current and then from highest current to lowest current. For each testpoint, the

resulting error shall be the mean of these measurements. For Imax, the maximum

measurement time shall be 10 minutes including stabilizing time.

2.4 Minimum test program

The minimum test program consists of:

a) No load check

For this test, there shall be no current circuit. The test shall be performed at Vnom.

27

For electricity meters with test output of the meter shall no produce more than one

pulse. For an electromechanical meter, the rotor of the meter shall not make a

complete revolution.

An electricity meter with more than one connection mode shall be tested in all modes.

For transformer operated meters with primary rated registers where the value of k

(and possibly Vnom) are given as primary side values, the constant k (and Vnom) shall be

recalculated to correspond to secondary side values (of voltage and current)

b) Starting current check

The test is performed at Ist and unity power factor

For initial verification of meters produced from a continuously operating process

resulting in a large number of identical units, it is sufficient from the error curve Ist to

Imin to be recorded on a sample batch every 3 months for the particular meter type.

For initial verification of meters produced by other means, it will be sufficient if the

meter is observed to run continuously when the starting current is applied.

c) Current dependence

Meters shall comply with the accuracy requirements of Table 2. As minimum these

shall be checked at the following currents:

Imin, PF = 1;

Itr, PF = 1;

Itr, PF = 0.5 inductive;

10 Itr PF = 1;

10 Itr PF = 1;

Imax PF = 1;

Imax PF = 0.5 inductive;

In the case of three phase meters with alternative single phase connection mode or

which are being used as two phase meters, this test shall be performed separately for

each phase at:

10 Itr, PF = 1 and

10 Itr PF = 0.5 inductive

28

For meters with alternate connection modes, such as one phase connections for poly

phase meters being used as two phase meters, this test shall be performed separately

for each connection mode.

d) Check of the register

If test (pulse) outputs are used for tests of accuracy requirements, a test must be

performed to ensure that the relation between the basic energy register and relevant

test output (s) complies with that specified by the manufacturer.

The energy put through the meter shall be calculated using the number of pulses from

the test output; the relative difference must not be greater than one tenth of base

maximum permissible error.

The test shall be performed at a single arbitrary current I ≥ Itr

3.0 Reference conditions for initial verifications in a laboratory

Reference conditions and load conditions for initial and subsequent verifications in a

laboratory are given in Table 4 and 5.

Table 4: Reference conditions and their tolerances for initial verification

Quantity Reference conditions Tolerance

Voltage (s) Vnom ± 2%

Ambient temperature 23ºC ± 5ºC

Frequency Fnom ± 0.5%

Wave form Sinusoidal d ≤ 2%

Electromagnetic RF fields 30 kHz – 6 Ghz 0 V / m < 2 V / m

Operating position for instruments sensitive to

position

Mounting as stated by

manufacturer

± 3.0 º

Phase sequence for poly phase meters L1, L2, L3 -

Load balance Equal current in all circuits ± 5% and ± 5º

Table 5: Load conditions and their tolerance in tests for initial verification

Current (s) Current range of device under test Class 2,1 : ± 10%

Class 0.5, 0.2 : ± 10%

Power factor Power factor range of device under test Current to voltage phase

difference ± 5 o

29

3.0 Additional Requirements For Statistical Verifications

This section contains additional requirements for verification on a statistical basis.

3.1 Lot Acceptance

A lot shall consist of meters with homogenous characteristics. All meters that comprise the lot

shall correspond to the same type approval, and shall have the same year of manufacture.

3.2 Samples

Samples shall be taken randomly taken from a lot

3.3 Statistical testing

The statistical control shall be based on attributes. The sampling system shall ensure:

An Acceptance Quality Level (AQL) of not more than 1%; and

A Limiting Quality (LQ) of not more than 7%

The AQL is the maximum percentage of non conforming items in a lot at which the lot has a

probability of 95% to be accepted.

The LQ is the percentage of non conforming items in a lot at which the lot has a maximum

probability of 5% to be accepted.

Examples are given below based on a lot of 1000 meters

Number of meters tested 40 70 100 1000

Maximum number of non conforming meters 0 1 2 10

30

ANNEX 1: NEW A PPROVAL REQUIREMENT FOR ELECTRICITY METER

Pattern ApprovalProcess by

National M easurementStandard Laboratory

(NM SL)

Certificate of Approvalfrom Commission

Application forPattern Approval to

NM SL

Product CertificationProcess by Accredited

Certification Body(ACB)

New meter

Pattern ApprovalProcess

Document submission:-Type Test Report-Pattern document-Other supporting

document

Issue Certificate ofPattern Approval

Yes

No

Register withDagangnet

Document submissionthrough online, e-permit:

-Type Test Report

Certificate ofApproval process

Issue Certificate ofPattern Approval

Application forProduct Certification

to ACB

Document submission:-Certificate of Pattern Approval

-Certificate of Approval (Commission)-Type Test Report

DocumentEvaluation

Factory Audit by ACB jointly withCommission.

Pre-requisite:-Authorised M anufacturer shall have

Accredited Laboratory-Product sample for conformity test

-Audit Evaluation-Conformity Test

-Award licence for the productto be affixing with Certified M arking-Yearly renew and the audit will be

performed once a year

No

Yes

Yes

Yes

No

No