Describe about relay testing by primary and secondary injection

Question

Accepted Answer

Relay testing by primary and secondary injection involves injecting current into the relay to test its functionality.

Primary injection testing involves injecting a high current directly into the relay to simulate a fault condition.
Secondary injection testing involves injecting a low current through the relay's input terminals to test its response.
Primary injection testing is more accurate but requires specialized equipment, while secondary injection testing is simpler and more commonly used.
Examples of primary injection testing equipment include Omicron CMC 356 and Megger SVERKER 750, while secondary injection testing equipment includes Omicron CMC 256plus and Megger FREJA 300.
Relay testing by primary and secondary injection is essential to ensure the proper functioning of protective relays in electrical systems.

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