ENA TS 48-4 : ISSUE 5 2016

Defines the design, performance, testing requirements and application of direct current auxiliary relays intended to act as independent trip relays. The trip relays will usually be initiated by the associated protection equipment. They are intended to provide fast, simultaneous, signals to the circuit-breaker and all associated protection, control and indication systems that require initiation following operation of the associated protection equipment. It is intended to apply to relays on the transmission and distribution systems.