PROT 401 provides an overview of the principles and schemes for protecting power lines, transformers, buses, generators, and motors. It also reviews basic power system concepts and describes. 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. The courses are designed to provide a practical and theoretical background to help engineers design. Protective Relays - Technical Seminar Nov 2016 - Copyright: IEEE 2 Abstract: Protective relays and devices have been developed over 100 years ago to provide “lastline”of defense for the electrical systems.