Is it normal for GFCI receptacles to explode and burn?

Question

I noticed my tooth brush wasn't charging one morning and none of the plugs in my bathroom were getting power, I went down to the circuit box and saw a flipped breaker so I flipped it back and it immediately tripped again. I tried it once more with the same result so I started to investigate the plugs in my house to see if anything was obviously wrong.

The external GFI on my deck had obvious signs of smoke on the siding so I disassembled the outlet and the entire back of the GFI blew out.

Is that a normal failure mode? Could it be a manufacture defect / installation issue?

There was obviously a lot of heat as the wire connectors appear scorched and the box is filled with a thick black soot.

Do I need to worry about additional damage to the wires beyond what is visible in the box or can I just remove the damaged wires and install a new GFI? Time to call an electrician?

Additional GFI Outlet Images

Answer 1

This happens all the time if an exterior GFCI is not weather-resistant. I've never had a weather resistant GFCI go up in smoke.

Yes, they can be in a metal box, but they still should be marked WR (weather resistant) - this means the electronics inside are coated to reduce the chances of moisture causing exactly what happened with your GFCI.

If it had shorted to the box, the metal screw would have arced and tripped the breaker. If it had shorted on the load side, it would have tripped the GFCI. But, in this case, enough moisture got in and the electronics shorted and let the magic smoke out.

Last item on the list is that it should have an in-use cover or an extra duty cover, that allows a cord to be plugged in with the cover protecting from rain.

In this case, replace your GFCI with a WR rated GFCI and add an in-use cover to greatly reduce the chance of this happening again. In some jurisdictions the local ordinances require the outlet itself to be GFCI so it can be reset (not running cords inside because of tripping the GFCI in wet grass with an electric mower is the "why" the inspector told me).

Answer 2

Move the GFCI

GFCIs have sensitive electronic components, as you found out the hard way. A regular outlet does not. If you can move the GFCI protection to an indoor location and then replace this with a regular receptacle, that would solve the problem permanently while still protecting against ground faults. Two options:

• Earlier in the chain. If there are other receptacles as part of this circuit before this outlet (e.g., possibly the bathroom that is on the same circuit), replace one of those with a GFCI receptacle. Just make sure that you use line vs. load correctly so that this receptacle is protected (on load screws).

• At the breaker. If you have sufficient space in your panel, replace the regular breaker with a GFCI breaker. That will protect the entire circuit.

As already noted, you should have an in-use cover on any outside outlet. This will help prevent nuisance trips due to moisture, though it is not a 100% cure-all and therefore moving the GFCI inside makes sense in any case.

Based on additional comments: It appears that the bathroom receptacle already has GFCI. If that is the case then (a) no need for a GFCI breaker and (b) need to check whether the outdoor receptacle (and any others in the circuit) is pigtailed to share the line connection or is actually using load. If the outdoor receptacle connects via load then it is already protected. Open up the bathroom receptacle box. If there are wires on both line and load, then wire up an ordinary receptacle in the outdoor location. Make sure it works. Then press the TEST button in the bathroom.

If the outdoor receptacle responds to the bathroom TEST button (i.e., when TEST is pressed, both bathroom & outdoor have no power, when RESET is pressed both bathroom & outdoor have power again) then you do not need a GFCI on the outdoor receptacle because it is already protected in the bathroom. Only one is needed but keep in mind that it protects "outward" - i.e., if the sequence is breaker->bathroom->outdoor then a GFCI breaker or a bathroom GFCI will protect bathroom and outdoor, but a GFCI outdoor will NOT protect the bathroom (though as we've discussed, you shouldn't put the GFCI outdoors anyway).

Answer 3

Exploding and burning equipment is not normal at all. Except for cases you are pyrotechnist and it burned/exploded intentionally.

There is no shame to admit limited knowledge about electricity and call an electrician to fix the issue. To be honest, this is the only sane way to go, unless you know what you are doing and why you are doing it bloody well. Shame is when one does not admit lacking knowledge and sets own house on fire accidentaly.

Any receptacle, connection and device shall be tested for a proper IP code to its use. Indoor receptacles are sufficient with code IP30 (protection against tools with diameter greater than 2.5 mm and no protection against water), for outdoor receptacles look for code IP65, IP68 for being sure. Materials are usualy not the concern here - the interior shall be dust-free and dry and the parts are well insulated when dry and clean (IP00).

Your receptacle was IP30 at most - no dust protection and no water protection. What happened to you was crossing the circuits within your receptacle by rainwater mixed with dust. This is conductive enough to shortcircuit anything behind the receptacle while resistant enough to heat significantly.

As other sugested, move the GFCI circuit indoors and use common receptacle outdors. The whole receptacle setup - box, receptacle and wiring - shall be code IP65 and more. If you move the GFCI only your breakers will be down quite often. The only improvement will be not burning the GFCI to ashes.