Electrical Protection

The ‘Hand Book’ 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 schemes like differential, restricted, directional and distance relays are explained with sketches. The norms of protection of generators, transformers, lines & Capacitor Banks are also given. The procedures of testing switchgear, instrument transformers and relays are explained in detail. The close and trip, indication and alarm circuits for variety of Circuit breakers indicating ferrule numbers are also included. All relevant information and circuit diagrams necessary for trouble shooting are also given.

We have more than 25 years experience, each in protective relaying and included a lot of information by way of original contribution apart from collection of useful information from a large number of reference books, manuals of manufacturers, etc. and it is hoped that this Hand Book will serve as a useful guide for all practicing Engineers.

We thank Sri B.Babu, Special Officer (Protection), Sri Vivekananda and Sri Sachidanandam, Divisional Engineers, APGENCO, Sri M.Gopal Rao, Chief Engineer, Sri L.M.Sastry and Sri J.Dakshina Murthy, Superintending Engineers, APTRANSCO for their valuable advise in preparation of this book. We also thank Sarvasri G. Seshagiri Rao, Divisional Engineer, M.Jagan Mohan Rao, Assistant Divisional Engineer, K.Srinivasa Rao, V.Venkateswarlu and Mrs.Shilpa, Assistant Engineers of APTRANSCO, Sri V.R.Rao and Sri Diganta of PGCIL for patiently going through the Hand Book and for their valuable suggestions in bringing out this Book. We specially thank Dr.Bhuvanaika Rao, APGENCO for his contribution of the chapter on Excitation & Voltage Control. Our special thanks to Sri M. Sreenivasa Reddy and Sri A.Bhaskar J.P.Os who has