Protective relays -- demo unit (SEL-501 relay time overcurrent trip)

This project incorporates both electromechanical and solid-state overcurrent relays to trip two circuit breakers conveying 120 VAC power to common loads (e.g. vacuum cleaner, hair dryer, or anything else drawing substantial current). The purpose is to demonstrate the operation of protective relays, and to serve as a system we can routinely calibrate.

[@aljohnson3717]

By far you are the best teacher your lucky students could have ever had! Great job!

[@fohdeesha]

great narration, clear and concise

[@aljohnson3717]

One little correction. At 3:43 you call TD is 3 seconds. This is not exactly correct, since its unitless number, three in this particular case. You will have operation time (in seconds or cycles of 60Hz) calculated based on the formula provided.

[@georgechoquette5735]

Well explained. Thanks

[@salmaakther4478]

Could you post the connection diagrams of this setup please. This would help me lot. Thanks and keep it up.

[@MD-cd7em]

GOOD VIDEO

[@ricardogalicia322]

What happens if we have a CT ratio of 1:1

[@aljohnson3717]

Then the Device PU Current will be 51PP*CTR = 3Amps*1 = 3Amps. Hope this helps.

[@ricardogalicia322]

@@aljohnson3717 Thanks!

[@gpadepedro]

Could you post the connection diagrams of this setup please. This would help me lot. Thanks and keep it up.

[@jyotielectrical7393]

th-cam.com/video/N9S34Iacntc/w-d-xo.html