BS EN IEC 62053-24:2021+A11:2021

This part of IEC 62053 applies only to static var-hour meters of accuracy classes 0,5 S, 1 S, 1, 2 and 3 for the measurement of alternating current electrical reactive energy in 50 Hz or 60 Hz networks and it applies to their type tests only.

This document uses a conventional definition of reactive energy where the reactive power and energy is calculated from the fundamental frequency components of the currents and voltages only (see Clause 3).

NOTE 1 This differs from IEC 62053-23, where reactive power and energy is only defined for sinusoidal signals. In this document reactive power and energy is defined for all periodic signals. Reactive power and energy is defined in this way to achieve proper reproducibility of measurements with meters of different designs. With this definition, reactive power and energy reflects the generally unnecessary current possible to compensate with capacitors rather than the total unnecessary current.

NOTE 2 For other general requirements, such as safety, dependability, etc., see the relevant IEC 62052 or IEC 62059 standards.

This document applies to electricity metering equipment designed to:

• measure and control electrical energy on electrical networks (mains) with voltage up to 1 000 V AC;

NOTE 3 For AC electricity meters, the voltage mentioned above is the line-to-neutral voltage derived from nominal voltages. See IEC 62052-31:2015, Table 7;

• have all functional elements, including add-on modules, enclosed in, or forming a single meter case with exception of indicating displays;

• operate with integrated or detached indicating displays, or without an indicating display;

• be installed in a specified matching socket or rack;

• optionally, provide additional functions other than those for measurement of electrical energy.

Meters designed for operation with low power instrument transformers (LPITs as defined in the IEC 61869 series) may be considered as compliant with this document only if such meters and their LPITs are tested together and meet the requirements for directly connected meters.

NOTE 4 Modern electricity meters typically contain additional functions such as measurement of voltage magnitude, current magnitude, power, frequency, power factor, etc.; measurement of power quality parameters; load control functions; delivery, time, test, accounting, recording functions; data communication interfaces and associated data security functions. The relevant standards for these functions may apply in addition to the requirements of this document. However, the requirements for such functions are outside the scope of this document.

NOTE 5 Product requirements for power metering and monitoring devices (PMDs) and measurement functions such as voltage magnitude, current magnitude, power, frequency, etc., are covered in IEC 61557-12. However, devices compliant with IEC 61557-12 are not intended to be used as billing meters unless they are also compliant with the IEC 62052-11:2020 and one or more relevant IEC 62053-xx accuracy class standards.

NOTE 6 Product requirements for power quality instruments (PQIs) are covered in IEC 62586-1. Requirements for power quality measurement techniques (functions) are covered in IEC 61000-4-30. Requirements for testing of the power quality measurement functions are covered in IEC 62586-2.

This document does not apply to:

• meters for which the voltage line-to-neutral derived from nominal voltages exceeds 1 000 V AC;

• meters intended for connection with low power instrument transformers (LPITs as defined in the IEC 61869 series) when tested without such transformers;

• metering systems comprising multiple devices (except LPITs) physically remote from one another;

• portable meters;

NOTE 7 Portable meters are meters that are not permanently connected;

• meters used in rolling stock, vehicles, ships and airplanes;

• laboratory and meter test equipment;

• reference standard meters;

• data interfaces to the register of the meter;

• matching sockets or racks used for installation of electricity metering equipment;

• any additional functions provided in electrical energy meters.

This document does not cover measures for the detection and prevention of fraudulent attempts to compromise a meter’s performance (tampering).

NOTE 8 Nevertheless, specific tampering detection and prevention requirements, and test methods, as relevant for a particular market are subject to the agreement between the manufacturer and the purchaser.

NOTE 9 Specifying requirements and test methods for fraud detection and prevention would be counterproductive, as such specifications would provide guidance for potential fraudsters.

NOTE 10 There are many methods of tampering with meters reported from various markets; designing meters to detect and prevent all kinds of tampering would lead to unjustified increase in costs of meter design, verification and validation.

NOTE 11 Billing systems, such as, smart metering systems, are capable of detecting irregular consumption patterns and irregular network losses which enable discovery of suspected meter tampering.

NOTE 12 For transformer operated meters paired with current transformers (CTs) according to IEC 61869-2:

• the standard CT measuring range is specified from 0,05 In to Imax for accuracy classes 0,1, 0,2, 0,5 and 1 and these CTs are used for meters of class 1, 2 and 3 according to this document;

• the special CT measuring range is specified from 0,01 In to I max for accuracy classes 0,2S and 0,5 S and these CTs are used for meters of class 0,5 S and 1 S according to this document;

• combinations of standard CTs and meters of class 0,5 S and 1 S are subject to an agreement between manufacturers and purchasers.

NOTE 13 This document does not specify emission requirements, these are specified in IEC 62052-11:2020, 9.3.14.