1 Scope
This part of IEC 61557 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 of PMDin 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.
Additionally, this document specifies requirements for measurement functions dedicated
to metering and monitoring of electrical parameters called power metering and monitoring function (PMF) which can be embedded in equipment (EPMF) that is not classified as PMD and for which the main function is not power metering and monitoring.
Requirements for power metering and monitoring function (PMF) and additional requirements for equipment embedding power metering and monitoring function (EPMF) are described inAnnex H.
The power metering and monitoring devices (PMD) for electrical parameters described in this document are used for general industrial and commercial applications.
The power metering and monitoring devices (PMD) can be associated with sensing devices such as but not limited to instruments transformers
compliant to IEC 61869 series of standards or with transducers compliant to IEC 60688.
This document does not address functional safety and cyber security aspects.
This document is not applicable to:
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— 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
inIEC 62053 (all parts);
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— the measurement and monitoring of electrical parameters defined inIEC 61557‑2 to IEC 61557‑9 and IEC 61557‑13 or inIEC 62020;
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—
power quality instrument (PQI) according IEC 62586 (all parts);
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— devices covered by IEC 60051 (all parts) (direct acting analogue electrical measuring instrument).
NOTE 1 Generally such types of devices are used in the following applications or for the following general needs:
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— energy management inside the installation, such as facilitating the implementation
of documents such as ISO 50001 and IEC 60364‑8‑1;
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— monitoring and/or measurement of electrical parameters;
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— measurement and/or monitoring of the quality of energy inside commercial/industrial
installations.
NOTE 2 A measuring and monitoring device of electrical parameters usually consists of several
functional modules. All or some of the functional modules are combined in one device. Examples of functional modules are:
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— measurement and monitoring of several electrical parameters simultaneously;
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— energy measurement and/or monitoring, as well as sometimes compliance with aspects
of building regulations;
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— alarms functions;
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—
demand side quality (current and voltage harmonics, over/under voltages, voltage dips and swells, etc.).
NOTE 3
PMD are historically called power meter, power monitor, power monitor device, power energy
monitoring device, power analyser, multifunction meter, measuring multifunction equipment,
energy meters.
NOTE 4 Metering, measuring and monitoring applications are explained inAnnex A.