can someone explain to me the purpose of the 10 ohm resistor in a HRG test circuit that intentionally grounds a phase? I understand how you size the pulse and continuous ground resistors depending on what type of HRG it is (5A cont w/ 5A pulse, 10A cont w/ 10A pulse) but can't seem to figure out what is going on with the test circuit.
480 HRG Test Circuit Resistor
- Thread starter MMC2258
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Updated Picture
Noticed the picture was too small. here is a larger version
http://imgur.com/a/DRwjJ
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SG-1
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- Ware Shoals, South Carolina
Resistors serve one purpose in circuits, that is to limit current to a predetermined value.
Suppose a ground fault was in progress on A-phase, but the HRG did not alarm, it has failed.
An operator comes to test the HRG, when he pushes the button or turns the switch to close the 43TX CR4 contact the resistor prevents a phase-A to-phase-B fault at the 43TX CR4 contact by limiting the current as described by Ingenieur.
Suppose a ground fault was in progress on A-phase, but the HRG did not alarm, it has failed.
An operator comes to test the HRG, when he pushes the button or turns the switch to close the 43TX CR4 contact the resistor prevents a phase-A to-phase-B fault at the 43TX CR4 contact by limiting the current as described by Ingenieur.
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