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 - 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. They are intended to quickly identify a fault and isolate it so the balance of the system. For a long power line, symmetrical built and symmetrical loaded in the three phases, voltage and current variation along the line can be expressed as shown in fig. 2, with corresponding formu-las. In these formulas the propagation of speed is included as a variable. where “ R ”, “ X ”, “ G ” and “. Protection systems are used to isolate faulted parts of the system, protect the electric system from instability, and minimize equipment damage. It covers standard codes, wiring practices, and norms for protecting generators, transformers, and lines, and provides detailed. Long term cost reduction (TCO) for trainings and maintenance by reduce variety of relays A fast and selective arc fault mitigation for air-insulated LV & MV switchgear and Relion protection and control relays and sensor technology protect staff and plant facilities for many years.