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Somewhat derivative of How can I trip a breaker from the outlet, how could someone relatively safely and quickly, with basic tools, trip a breaker at a GFCI outlet (relatively safely meaning not getting electrocuted or starting a fire)?

If something conductive and grounded is touched to the line or a drop of water falls on it, it's just going to trip the outlet, but there will still be power to it, right? That's the point of the GFCI.

Thanks for answering the question, as well as all advice to not and never do such a thing.

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    Why do you want to trip the breaker, instead of just finding the breaker at the panel and turning it off? – ThreePhaseEel Aug 13 at 22:35
  • Hello, and welcome to Home Improvement. Six answers on your first question; good work! And, you should probably take our tour so you'll know how best to participate here. – Daniel Griscom Aug 14 at 14:22
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You want to trip the overcurrent detector (breaker) serving a GFCI outlet.

No. Don't do it.

What you're looking for is so similar to the other question that it really is a duplicate. It is wrong for all the reasons that one is wrong (and not insane in a certain industrial setting for the reasons I describe in my answer there).

The presence of GFCI is irrelevant. (though of course if you use the hare-brained scheme in the other question, you have a good chance of frying the GFCI's innards; it will cheerfully allow the overcurrent if balanced, but its detection circuit will fail before the breaker will).

Your parameters for "safety" are too narrow

You are ignoring the likelihood of failing a circuit due to the overload opening a wire connection, or worse, setting the stage for a future arc-fault problem that could burn down the house the next time you load the circuit within reason.

Then there's the matter of arc flash right there in your face.

Plug in a radio, and snap breakers

The way you solve this is by plugging in a radio and snapping breakers off until the radio stops. Pretty simple. If you don't have a radio, a vacuum cleaner will also do.

You could also plug in two 1500W heater-fans and wait 20 minutes. That will trip any 15A or 20A circuit eventually. But again you are risking the same kind of wiring failures discussed in "too narrow" above.

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The GFCI section will trip if any current leaves the hot wire without returning on the neutral wire.

The circuit breaker will trip if more current leaves the hot wire than its trip rating, such as 15 or 20A.

So, if you want to induce a trip on the breaker without tripping the GFCI outlet, you simply need to draw more current than the breaker's rating from the hot wire, and return all of that current through the neutral wire. Shorting the hot and neutral with a jumper wire inside a plug body, and plugging this into the outlet would suffice.

This should be relatively safe assuming the breaker works. If you're not sure if the breaker works, (which I suspect might be the case, since why else would you want to do this?), then this might not be safe -- if the breaker fails to trip before the wire overheats, you might start a fire inside your walls. I would especially not recommend doing this if you have breakers of a brand known to have tripping problems, such as FPE or Zinsco.

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Honestly, the safest way (assuming this is a receptacle circuit) is to use a plug-in wiring tester with a GFCI test button. Plug in, push button, done. No safety issues or hassles. And you really should own one as an electrical DIYer anyways.

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Best method for homeowners would be to plug in something with noise ( Floor fan set on "high", vacuum cleaner, corded drill motor ) and firstly look at your panel breakers to see if the circuit you're interested in turning off is labeled... If you see a "potential candidate" breaker, then turn that one off first.

If not, listen, turn one off and if your device stops making noise, go back to that device and make certain it's off.

Otherwise, turn the breaker back on, and check all the rest of them in the same above mentioned manner.

I also got somewhat hinted that you might be talking about testing the GFCI, but was not so sure... But if that was it, every GFCI has a "test" and a "reset" button on them. Push accordingly.

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Tripping a GFCI receptacle disconnects the hot power conductor at the receptacle. All GFCI receptacles have a TEST button which when pressed trips the GFCI receptacle.

Tripping a GFCI breaker disconnects the hot power at the breaker (in the panel) for the entire circuit. There are devices called GFCI testers which when plugged into a GFCI protected circuit and activated will trip the GFCI breaker.

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I suppose this answer more properly belongs on the linked question rather than here, but.. if you really want to trip the overcurrent breaker and not trip the GFCI outlet, then the only thing to do is introduce an overcurrent. A dead short as proposed by answers in that related question is indeed an overcurrent, but it's also rather extreme.

The thing to know about overcurrent breakers, and fuses too, is that their response time is inversely proportional to the amount of overcurrent (as a first-order approximation). Consult a manufacturer's data sheet for precise numbers, but here are some order-of-magnitude estimates to convey the idea. A circuit breaker might carry 5% overload for minutes or even hours before tripping. A 100% overload might be carried for several seconds, while a 300% overload might trip in several tens or hundreds of milliseconds.

Overcurrent protection exists to limit the damage to wiring and devices and to minimize the risk of fire, but it doesn't guarantee to prevent all overcurrent-related damages. A decision to test a breaker in this way would have to select an overcurrent threshold by weighing time-to-trip against the potential for damage. The technique would then be to introduce a load that can safely dissipate power until the breaker does trip, then (somehow?) inspect for and repair any damages caused by the exercise.

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