IEC TS 63346-2-1:2026

IEC TS 63346-2-1:2026 establishes the general principles for the design of low-voltage auxiliary power systems (APS) with nominal voltages below or equal to 1 kV AC and 1,5 kV DC, and nominal frequency up to and including 60 Hz, so as to provide safe and correct operation for the intended use.
This document applies to the design of low-voltage auxiliary systems for
- substations, which are part of an electrical system, confined to a given area, mainly including ends of transmission or distribution lines, electrical switchgear and controlgear, buildings and transformers,
- converter stations,
- hydropower stations, where the gravitational energy of water is converted into electricity, and
- thermal power stations, where the thermal energy is obtained by burning fossil fuels.