DC supply & Trip Indications of 11KV MetalClad Switchgear according to WAPDA Specification P-44:96

• Supervision relay shall be provided for continuously monitoring the healthy conditions of breaker trip circuit and presence of DC supply on all applicable panels. The presence of healthy trip circuit shall be indicated by the continuous glow of a yellow lamp. The indicating lamps shall be of neon type with screwed base. The rating shall be 5 Watt at 150V or 260V DC depending on control and auxiliary supply voltage.
• One hooter and its acknowledge and cancelling arrangement shall be installed in the incoming panel to indicate failure of DC main supply, DC supply to any panel and failure of healthy trip circuit and tripping of any breaker. This arrangement should be self contained and securely fixed to the panel. The alarm cancelling arrangement shall be flush mounted on the front of the panel.
• For circuit breaker fitted with AC series trip mechanism, auxiliary contacts shall be provided in the protective relay for operation of a hooter, installed in the incoming panel, to indicate breaker trip. The contact shall be suitable for operation for the hooter.