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Internal wiring of relay protection devices
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. Also principles of various protective relays and schemes including special protection. Protective relays and devices have been developed over 100 years ago to provide “lastline”of defense for the electrical systems. They are intended to quickly identify a fault and isolate it so the balance of the system continue to run under normal conditions. The selection and applications of. presentation of protection and control relaying. In the wiring diagrams that are shown in this publication, the type of Allen-Bradley® Guardmaster® device is shown as an example to illustrate the circuit principle.