This document specifies the requirements for the design, construction and installation of the following types of DC and AC electrical systems, installed on small craft either individually or in combination: a) extra-low-voltage direct current (DC) electrical systems that operate at nominal potentials of 50 V DC or less; b) single-phase alternating current (AC) systems that operate at a nominal voltage not exceeding AC 250 V. This document does not cover the following: — electrical propulsion systems of direct current less than 1 500 V DC, single-phase alternating current up to 1 000 V AC, and three-phase alternating current up to 1 000 V AC, which are addressed by ISO 16315; — any conductor that is part of an outboard engine assembly and that does not extend beyond the outboard engine manufacturers supplied cowling; — three-phase AC installations that operate at a nominal voltage not exceeding 500 V AC, which are addressed by IEC 60092-507.