09 Feb

Testing Electromechanical Relays

Testing Electromechanical RelaysTesting electromechanical relays involves the following steps:
• An inspection of the relay for loose screws, friction in moving parts, iron filings between induction discs and permanent magnets, and any evidence of damage to the relay.
• Correct settings should be applied or verified.
• Pickup Test: measures the point where contacts just close for a particular parameter
• Timing Test: measures the time to close contacts at a particular multiple of pickup applied to the relay.
• Instantaneous Test: if used, measures the point where instantaneous contacts close with no time delay
• Test of target and seal-in unit: if used, target indicates the relay has operated and seal in contact holds contacts closed until breaker trips.
• Test of Tripping Circuit.

Protective relays should be acceptance tested prior to being placed in service. Thereafter, they should be tested periodically to ensure reliable performance.  In normal industrial applications, relays should be tested at least every 2 years. In critical systems, testing should be conducted at least annually.

Contact Reuter Hanney, the electrical power specialists, today at bids@reuterhanney.com for a review of your company’s electrical equipment needs and to learn more about safety, and safety maintenance procedures.