IEC Relay Test Standards for 220V Auxiliary Supply: What You Need to Know
A protection relay doesn’t work without its auxiliary supply. The CT and VT measurements feed the analog inputs, but the processor, the display, the communications, and the trip contacts all run off the auxiliary voltage. In most of the world, that auxiliary voltage is 220V — either 220V DC from a substation battery or 220V AC from a… Read More: IEC Relay Test Standards for 220V Auxiliary Supply: What You… »