BS PD IEC/TS 62257-9-4:2016, which is a technical specification, specifies the general requirementsfor the design and the implementation of a user's installation.This part of IEC 62257 applies to single phase user's electrical installations with maximumpower of 500 VA, in Decentralized Rural Electrification Systems (DRES).NOTE For installations above 500 VA in decentralized electrification systems, IEC TS 62257-5 applies.This part of IEC 62257 is applicable to installations supplied by an a.c microgrid (120 V or220 V or 230 V or 240 V) and to installations encompassing their own single-unit a.c.micropower plant (120 V or 220 V or 230 V or 240 V) or d.c micropower plant (12 V or 24 V).The part of IEC 62257 applies neither to the electric power production and distributioninstallations described in the clauses concerning micropower plants and microgrids, nor touser electrical equipment. It details the rules governing the design and construction ofconsumer's electrical installations for the purpose of ensuring the safety of persons andproperty, and satisfactory operation in accordance with the purpose for which the installationsare designed.It applies to new installations and modifications of existing installations.Cross References:IEC 60269IEC 60364-5-52IEC 62257IEC/TS 62257-5IEC/TS 62257-7IEC/TS 62257-7-1IEC/TS 62257-9-3