A comprehensive testing program should simulate fault and normal operating conditions of the relay. Acceptance testing, commissioning, and startup will include control power tests, current transformer and potential transformer tests, and any other device testing associated. Protective relays and devices have been developed over 100 years ago to provide “last line” of defense for the electrical systems. This is why protection relays must undergo thorough tests throughout their entire lifecycle – from development and manufacturing to commissioning and regular maintenance. For the Power Systems Technician, the ability to effectively inspect and test protective relays is paramount. As the demand for reliable electric power grows. Every relay has a provision of setting. Setting determines pick-up value/time. Tests are conducted by the manufacturer at manufacturer s works, and by the user at site during commissioning and periodic maintenance.
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