BS 8431:2010 Electrical static meters for secondary metering and sub-metering. Specification
Energy meters, mainly kWh meters, are a common requirement of electrical control panels, in many cases as part of a multiple function unit. Energy measurement is recognized as an essential element of energy management. This assists with the drive to reduce carbon emissions and to improve the commercial efficiency of manufacturing, commercial organizations and public services.
Although the basic principles of energy management are well understood, for energy to be well managed it needs to be adequately measured. With the common use of electronic equipment, and of electronically controlled loads, the measurement techniques to measure such loads are not generally understood. The effects of incorrect measurement techniques are even less well understood. Unless energy meters are correctly specified, there is a risk that readings obtained in good faith could be incorrect and misleading.
BS 8431 specifies requirements for newly manufactured electronic secondary meters or sub-meters. It covers meters which measure either electrical energies alone or electrical energies together with other electrical parameters associated with the energy. It applies to meters that measure active energy, apparent energy, reactive energy (capacitive, inductive and/or total), and ampere squared hours (A²h). It also applies to the measurement of current, voltage, active power, apparent power, reactive power (capacitive, inductive and/or total), power factor, phase angle and frequency when measured in addition to an energy.
BS 8431 applies to all secondary meters and sub-meters for indoor and outdoor applications, both portable and permanently installed, for all power frequencies including d.c. It also applies to all registers, indicators, displays and outputs, and to the operation of test outputs.
It does not apply to primary meters, to data interfaces to the meter, or to load survey analysers or load survey meters. The reliability aspect is not covered in BS 8431.
Where the display and/or the memory is external or where other elements are enclosed in the meter case (such as maximum demand indicators, telemetering, time switches or remote control, etc.) BS 8431 applies only to the section of the meter concerned with measurement.
BS 8431 replaces DD 8431:2005 Electrical static meters for secondary metering and sub-metering. Specification.
Contents of BS 8431:
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Standard electrical values
5 Mechanical requirements
6 Climatic conditions
7 Electrical requirements
8 Electromagnetic compatibility (EMC)
9 Accuracy requirements
10 Safety requirements
11 Tests and test conditions
12 Marking
13 Accompanying documentation
Annexes
Annex A (normative) Tests of mechanical requirements
Annex B (normative) Tests of climatic influences
Annex C (normative) Tests of electrical requirements
Annex D (normative) Tests for electromagnetic compatibility (EMC)
Annex E (normative) Tests of accuracy requirements
Annex F (normative) Tests of safety requirements
Annex G (informative) Test schedule
Bibliography
List of figures
List of tables