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Relay Protection Design Guidelines
This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. This document supplements PJM Manual 07 which contains the minimum design standards and requirements for the protection systems associated with the bulk power facilities within PJM. The IEC standard for relay coordination provides clear guidelines and methodologies to ensure that protective relays work in harmony to isolate only the faulty section of the system while keeping the rest. Protective relays and devices have been developed over 100 years ago to provide “last line” of defense for the electrical systems.