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How is the relay protection from Panama Electric
Each relay provides the following functions: 87L protection that uses phase (87LP), negative-sequence (87LQ), and zero-sequence (87LG) differential elements to provide phase and ground fault protection. A practical guide to how protective relays detect faults, trip circuit breakers, coordinate protection zones, and improve power system reliability. Protective relays and devices have been developed over 100 years ago to provide “last line” of defense for the electrical systems. P&C System Description The P&C system uses multifunction relays with communications and programmable logic. It has a set of input terminals for one or more control signals, and a set of operating contact terminals.