IEC 63318:2022 This document specifies electrical systems that are intended to be used for electricity access and not connected to a public network such as product kits up to 35 V DC as specified in IEC 62257-9-5 and IEC 62257-9-8 for Tier 2 of the ESMAP Muti-Tier Framework for household electricity supply; and/or 48 V DC fixed installations, for Tier 3 of the ESMAP Muti-Tier Framework for household electricity supply. This document applies to Tier 2 and Tier 3 installations using SELV DC systems.