scope:

NVN-IEC/TS 62257-9-3 which is a technical specification, specifies the general requirements for the design and the implementation of the interface equipment within the user's installation which connects to a microgrid or the generating part of a standalone system. This interface is a part of the user's installation as shown in Figure 1. This part of IEC 62257 applies to simplified user's interfaces (distribution board) in electrical installations with maximum power of 500 VA in Decentralized Rural Electrification Systems (DRESs). This part of IEC 62257 applies to an interface equipment within the user's installation and which connects the user's installation to: - 240 V or 230 V or 220 V or 120 V a.c. microgrid, - the generating part - a.c. or d.c. - of a standalone installation. This equipment provides protection, isolation, and distribution functions.