Introduction to Relays – 8 minutes
Identifies five common relay elements. Identifies the functions of overcurrent, directional overcurrent, reclosing, voltage, and auxiliary relays.
Differential Relays – 13 minutes
Identifies what differential relays typically protect. Describes the condition that causes a differential relay to operate. Describes the basic operating principles of differential relays.
Transfer Tripping – 9 minutes
Describes the function of transfer tripping. Identifies the main components of a transfer tripping system. Identifies four communication channels used for transfer tripping and explains how they work. Identifies the main equipment associated with transfer tripping communication channels and describes the function of each type of equipment.
Distance Relays – 12 minutes
Identifies what distance relays typically protect. Describes the basic operating principles of distance relays, and the conditions that cause them to operate.
Pilot Wire Relaying – 7 minutes
Describes the function and operating principles of a pilot wire relaying system. Identifies the main components of a pilot wire relaying system.
Breaker Failure Relaying – 9 minutes
Identifies the function and the main components of a breaker failure relaying system. Describes the basic operating principles of a breaker failure relay, and of a timer relay in a breaker failure relaying system.