IEC 61557-12 Ed. 2.1 b:2021

Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC

Equipment for testing, measuring or monitoring of protective measures

Part 12: Power metering and monitoring devices (PMD)

IEC 61557-12:2018+A1:2021 specifies requirements for power metering and monitoring devices (PMD) that measure and monitor the electrical quantities within electrical distribution systems, and optionally other external signals. These requirements also define the performance in single- and three-phase AC or DC systems having rated voltages up to 1 000 V AC or up to 1 500 V DC.

These devices are fixed or portable. They are intended to be used indoors and/or outdoors. Power metering and monitoring devices (PMD), as defined in this document, give additional safety information, which aids the verification of the installation and enhances the performance of the distribution systems.

The power metering and monitoring devices (PMD) for electrical parameters described in this document are used for general industrial and commercial applications. This document does not address functional safety and cyber security aspects.

This document is not applicable for:

• electricity metering equipment that complies with IEC 62053-21, IEC 62053-22, IEC 62053-23 and IEC 62053-24. Nevertheless, uncertainties defined in this document for active and reactive energy measurement are derived from those defined in IEC 62053 (all parts);
• the measurement and monitoring of electrical parameters defined in IEC 61557-2 to IEC 61557-9 and IEC 61557-13 or in IEC 62020;
• power quality instrument (PQI) according IEC 62586 (all parts);
• devices covered by IEC 60051 (all parts) (direct acting analogue electrical measuring instrument).

IEC 61557-12:2018 cancels and replaces the first edition published in 2007. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:

• a) PMD-A has been withdrawn due the fact these devices are now mainly covered by the IEC 62586 series of standards.
• b) Three categories of PMD have been created with a list of minimum required functions for each category.
• c) Added a new Annex A explaining the different applications linked to the relevant standards and devices, and another new Annex C about the power factor conventions.