How do you know if a GFCI outlet is bad?

Answer 1

for USA, Canada and other countries running a 60 Hz supply service

The device could be faulty or it could be working perfectly, as they typically do. If you mess about with it without understanding how it works you could receive a life threatening shock. Another likely possibility, as GFCIs are extremely sensitive, is that you have plugged in a piece of equipment which is faulty and that equipment should therefore be thrown away.

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Depending on what is happening, there could be several possibilities:

A) You have put too many items onto the circuit the GFCI is protecting, so it cannot sense properly and trips, or

B) You have not had it installed correctly, and the Sense Ground wire has become corroded with time and moisture, or

C) The wiring that is further down the line, if it "protects" other sockets and circuits downstream from this one, have problems with the insulation breaking down, or

D) Something else is wrong and you need to call a competent person to advise on your home wiring.

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If the gfci trips this means there is more than 10mA current between the ground the hot and neutral wires which, in, say, a kitchen or outside the home or in some other damp area, usually means something got wet.

2. If the particular circuit's main circuit breaker has tripped then this particular GFCI outlet cannot be reset and it won't test either, with the power out. If you can reset the circuit's main circuit breaker at the panel, you may then find the GFCI works. A second outlet somewhere in the same room or elsewhere might also not have worked because it is connected to the load terminals of the tripped GFCI.

3. If the circuit's main circuit breaker at the panel can be reset and the GFCI still won't work then you may have a damaged GFCI or there may be some equipment still plugged into it - or into a second outlet somewhere in the same room or elsewhere - that has a fault. so if there is no equipment plugged in anywhere, either at or after the GFCI, get the GFCI replaced.

4. I suggest you probably should call an electrician.

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The Capacitor on a single phase motor (for a "fan", etc.) sometimes causes a GFCI to trip. Commercial Grade GFCIs are better suited to this application.

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Two other things can cause false tripping:

1. A noise filter or surge protector in the circuit after the GFCI bypasses high frequency noise to ground. This unbalances the current in the hot and neutral, tripping the device.

2. Dirt or insects inside the outlet box. One time I opened an outlet box that was tripping the GFCI even with no plug in the socket. The box was full of dead roaches. I removed the bugs, and the device started working normally.

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GFCI circuit breakers perform two functions. If it is a true circuit breaker it will prevent "over-current" conditions from overheating the wiring of your home and hopefully minimize the potential for fire. All circuit breakers and fuses are designed to 'trip' or 'blow' when an over-current condition exists. GFCI circuits have an additional function. To prevent or minimize the potential for hazardous shocks, GFCI circuits compare the current that goes across the two wires that make up the hot and common voltage lines of an outlet. If the current on the two wires does not match precisely, the assumption is that current is being lost to something outside of the circuit. This condition is called a "ground fault". In simple terms, it means that there is high potential that YOU are grounded, as in standing in a puddle of water, and YOU have touched the "hot" side of the circuit or the device somehow allows current to go outside of the normal voltage path. A ground fault can exist if an outside outlet has become wet with rainwater, or an outside extension cord is laying in water or an appliance is in the process of failing and voltage leaks to the ground wire. But as already mentioned, it can also indicate that the GFCI has failed, although that doesn't often happen.

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A GFCI [Ground Fault Circuit Interrupter] trips when it senses a ground fault. In a correctly wired circuit the return path should be on the neutral wire. The circuit will trip if the GFCI senses a difference in the current (amps) in the Black "hot wire" from what is returning in the White "neutral wire". The two current values should be the same unless you are leaking electricity, which is called a ground fault. This can happen in a wet location when electricity is using the water as its ground and not returning back through the neutral wire. Older motors can also leak electricity in to their motor housings. If the electricity is not returning through it's designed path then you may have a safety hazard and your GFCI is protecting you.

To test a tripping GFCI follow these steps.

1. Remove every appliance connected to the GFCI's circuit and then try to reset it. If the GFCI doesn't reset there may either be a wiring fault behind a socket outlet or your GFCI itself has become faulty.

2. Make sure what whatever you are plugging in to the GFCI is dry and not damaged.

3. Only plug in one item of electrical equipment at a time. If you are plugging in a defective item it will cause the GFCI to trip and that item should be replaced.

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From what this question is saying, the TEST button is doing its job - it is testing ( = checking) that the GFCI is working correctly!

After you have tested the device by pressing the TEST button you should be able to press the RESET button again - and DO NOT PRESS THE TEST button again - and everything should work.

Either your GFCI is bad [in which case replace it] or it is working perfectly.

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It is probably working. My sister had a similar problem. She just kept resetting until it held, but every time she got in her hot tub she got shocked.

Luckily she wasn't killed. It turned out to be the fly weights shorting out against the capacitor wires, turning the water into the hot leg. Don't mess around with this kind of problem.

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Another possible cause for tripping a GFCI is radio frequency energy. If you are close to a transmitting station this may occur. I have seen a GFCI trip when a car, equipped with a transmitter, pulled into a driveway and keyed up the transmitter. If the output is high enough and/or at a particular frequency, this may happen. If so, the GFCI(s) may need to be shielded.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 2

If a GFCI outlet is no longer providing power or is not resetting, it may be faulty. You can test it using a GFCI tester to see if it trips properly. Additionally, if it shows discoloration, cracking, or other physical damage, it may need to be replaced.

Answer 3

moisture,overload,improper wiring ,problem with circuit,groung fault,white wire copper touching bare ground wire The technical answer is a difference in the amount of current on the hot and the amount of current on the neutral.

Answer 4

To test a GFCI outlet, push the button that says TEST on it. If the power goes off, it is working and if it doesn't go off, it is not working (Call a qualified electrician to replace it). You should test a GFCI every month.

Answer 5

Of course it is possible. However, more often there is something external to the GFCI that causes the GFCI to trip. There may be other outlets connected to the GFCI or there may be moisture in circuit causing a ground fault. Open the box where the GFCI is located and see if there are any wires on the output side. If so remove them with the power off and see if GFCI trips when you turn power back on. If GFCI still trips, turn off power and remove GFCI entirely. Connect it to another working circuit and see if it still trips. If it does, you have a bad GFCI device. Never mess with wiring unless you are absolutely sure that the power is off.

Answer 6

You need to describe the problem you are having with outlet. Most common problems are loose wires at a screw or push type connector, a wirenut coming loose, screws on side touching metal or nicks in wires causing shorts. Occasionally the outlet itself is bad internally. I have seen this after lightning strikes.