Common use of Secondary Line Protection Clause in Contracts

Secondary Line Protection. Distance relaying protection will be provided via a high speed microprocessor based distance relay. This relay shall be set to be selective within the prescribed zones of protection based on system protection analysis. The relay will directly trip and block the closure of the breaker(s). The relay shall be of utility grade and meet Transmission Owner’s standards. Breaker Failure: Two independent primary and secondary breaker failure relaying systems provide redundant breaker failure protection. After a circuit breaker trip is initiated the breaker failure relay will begin a countdown timer. If the circuit breaker fails to open within a specified period, then the breaker failure relay will trip its associated lockout relay to trip and block closure of the adjacent and series line circuit breakers. The breaker failure relaying at the Xxxx Substation does not send direct transfer trip to the remote terminal substation. The series line breaker is provided to isolate stuck breakers from the 230kV system. The relay shall be of utility grade and meet Transmission Owner’s standards. Transfer Trip: During Phase I, the Xxxx Substation is connected via a tap to the MWP-2 line. The line will be tripped by MWP-2 line relay and breaker failure operations at Transmission Owner terminals. Breaker failure conditions at Transmission Owner terminals will be programmed to remotely trip the Xxxx Substation incoming breaker upon receiving direct transfer trip (DTT) signals from Xxxxxx Substation. Two independent communication channels will be provided for the DTT.