gfi outlets trip breaker in panel when tested

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Stevenfyeager

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Location
United States, Indiana
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electrical contractor
In an older house, a home inspector noticed the kitchen gfi also trips the circuit breaker when tested. Is this a concern? I'm not sure why it does this, but it does. I've never seen this.
Thank you.
 
If it’s a regular breaker you’ve got a problem.
Bad GFCI receptacle that shorts out when it trips.
 
I have never seen it either but I go along with the gfci is the problem. Change out the gfci receptacle and my bet is it goes away
 
Or, the neutral and the live are actually reversed on one of the outlets. Many times that happens, when you place a gfci outlet as lead but do not verify all the other outlets are properly wired as load. Another cause could be a shared neutral, although that usually trips the gfci more often in use than when testing.
 
GFI outlet is not noticing but, the tester device is tripping the main breaker for the circuit. In UK you have to prove polarity on circuits all the time in your 8nstallations and at your testing times, which in residential properties is like every three to five years right now... because the reverse polarity affects safety of the consumer. But, it is also the testing that sometimes highlights the likelihood of the crossed wiring... when testing a live circuit with an RCD or gfci tester if the breaker trips with the device then there is usually a polarity problem on the circuit... so you automatically deaden the circuit and run your polarity test to rule that out. If polarity is fine, then you look at replacing the RCD.
 
I wish I could print it out but it was taught to me around twelve years ago... not in code books but 8n a practical training class at my one job... Currently waiting to see if the local council is going to take me on for training as an inspector.. first interview went well..waiting for the new shortlist.. they had 2000 applicants for twelve positions, interviewed fifty of us in first round..lol..
 
Adamjamma said:
GFI outlet is not noticing but, the tester device is tripping the main breaker for the circuit. In UK you have to prove polarity on circuits all the time in your 8nstallations and at your testing times, which in residential properties is like every three to five years right now... because the reverse polarity affects safety of the consumer. But, it is also the testing that sometimes highlights the likelihood of the crossed wiring... when testing a live circuit with an RCD or gfci tester if the breaker trips with the device then there is usually a polarity problem on the circuit... so you automatically deaden the circuit and run your polarity test to rule that out. If polarity is fine, then you look at replacing the RCD.
Click to expand...
That is all fine and dandy, and probably a good idea to do said testing.

But older US installations that have a thermal mag breaker and a GFCI receptacle - the thermal mag won't care about low level leakage to ground or other circuits all it cares about is current through itself and it's trip curve. The GFCI won't care about polarity/ just that current leaving on one conductor returns on the other, within a tolerance range of 4-6 mA.

If one pressed the test button on the GFCI receptacle to do the testing - the only unbalance current is within the device itself and only the GFCI should trip on this test. Even if another GFCI were upstream it shouldn't be effected by this test.

If one introduced an actual leakage current as part of testing (which is what plug in GFCI testers do) then the GFCI should trip because of the leakage current it is supposed to be monitoring for, but a standard 15 or 20 amp thermal mag breaker upstream is not going to trip because of a ground fault of only a few milliamps.
 
Unless the gfci outlet has a short occurring because of the crosswire down circuit and the added voltage from the tester creates enough fault current in addition to the short circuit to trip the breaker.
As another poster stated.. you can just change out the gfci outlet and it will work... until it has tripped enough times, either from testing or actual faults, to create the internal short like the first one, due to the miswiring downstream.
Thus, correct the wiring if it is there, replace the outlet...
if no cross wiring is found, replace the outlet.
in both cases, the outlet has a fault, whether from miswiring downstream or from some other cause.
 
Adamjamma said:
Unless the gfci outlet has a short occurring because of the crosswire down circuit and the added voltage from the tester creates enough fault current in addition to the short circuit to trip the breaker.
....
Click to expand...
That is not a possibility on our systems. Cross wiring (reverse polarity) down stream of the GFCI device does not create a fault. A connection between the ungrounded and grounded conductor would be a fault that opens the breaker with or without a GFCI in the system. A GFCI tester does not add fault current that an thermal magnetic breaker could detect. The ground fault current introduced by a plugin type of tester is less than 15 mA. The push button tester built into the GFCI does not introduce an actual ground fault. It is a grounded to ungrounded connection via a resistor with one of the resistors connections upstream of the current sensor and the other downstream.
 
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