Electrical Question

[COcheesehead]

I have an outdoor electrical outlet on my roof. It was installed by our builder during construction so we could run heat tape on a flat roof section to keep ice from building up on the north side of the roof in winter.

The past two winters, I have plugged two strands of heat tape into the outlet. I went up on the roof yesterday and plugged one strand in. Works fine. Plugged the second strand, popped the GFIC Tried multiple things in the second outlet. Didn’t matter, the second thing into the outlet popped the GFIC

Any ideas why all of a sudden the outlet will work for only one plug?

 

[Car-Guy]

I have an outdoor electrical outlet on my roof. It was installed by our builder during construction so we could run heat tape on a flat roof section to keep ice from building up on the north side of the roof in winter.

The past two winters, I have plugged two strands of heat tape into the outlet. I went up on the roof yesterday and plugged one strand in. Works fine. Plugged the second strand, popped the CFI. Tried multiple things in the second outlet. Didn’t matter, the second thing into the outlet popped the CFI.

Any ideas why all of a sudden the outlet will work for only one plug?

First thought is the second plug is bad (shorted). Second thought is the GFCI sensor has gone bad. Third thought, it's something else.

 

[COcheesehead]

First thought is the second plug is bad (shorted). Second thought is the GFCI sensor has gone bad. Third thought, it's something else.

I flipped what I plugged in between the first and second outlet. It didn’t matter. It was always the second to plug that caused it to pop.

 

[Car-Guy]

Then I'll go with my second guess.

 

[CRLLS]

Shorted hot to neutral would not trip a GFCI. It would trip the circuit breaker. Unless they are one and the same. Leak from hot to earth would trip a GFCI. They do go bad. I had one go bad a couple years back with our Xmas lights. It was one of the outlet GFCIs located outdoors, not a breaker style.

Likely the GFCI has become too sensitive. I would change it out. would do.

 

[ERD50]

Is this a standard duplex outlet with GFI? And are both outlets wired together to one circuit (I think GFI are always together, can't be split like a normal duplex, but I'm not sure (but pretty sure)?

Are you really sure both heat strips are working? Do those heat tapes got hot enough, quick enough to be certain they are ON? I might try a regular desk lamp or something.

I'm not clear when you say "the second one" - is it one of the two outlets that will trip, or is it when you plug in two heat strips, regardless of the order of heat strips and plugs?

If both really work in either outlet alone, there might be a slight chance that both are a bit leaky to ground, but not enough for one to trip the circuit, but the sum of two is enough? Unlikely, but never say never.

-ERD50

 

[ERD50]

Another possibility - a leakage path from Neutral to ground on one outlet (but, I'd expect the Neutrals to be connected together?).

A path from N to ground wouldn't matter until something was plugged in, causing a current to go from Hot to that N, but getting some shunted to ground would trip the GFI. But w/o anything plugged in, there would be no current anyway, so no trip.

-ERD50

 

[COcheesehead]

Is this a standard duplex outlet with GFI? And are both outlets wired together to one circuit (I think GFI are always together, can't be split like a normal duplex, but I'm not sure (but pretty sure)? Yes

Are you really sure both heat strips are working? Do those heat tapes got hot enough, quick enough to be certain they are ON? I might try a regular desk lamp or something. I had a small fan I’m used to test both outlets and they work individually

I'm not clear when you say "the second one" - is it one of the two outlets that will trip, or is it when you plug in two heat strips, regardless of the order of heat strips and plugs? It’s the second of whatever I plug in. The device doesn’t matter

If both really work in either outlet alone, there might be a slight chance that both are a bit leaky to ground, but not enough for one to trip the circuit, but the sum of two is enough? Unlikely, but never say never.

-ERD50

My answers in red
The issue is beyond my pay grade. DW is calling an electrician.

 

[street]

Change out GFI. They get weak and stressed and just won't hold the current level and trips.

 

[COcheesehead]

Change out GFI. They get weak and stressed and just won't hold the current level and trips.

It worked as of last February when I unplugged the heat tape. Could it go bad just in that time frame?

 

[street]

I could there are contacts and might be a little corrosion going on. I guess what I would do is take an extension cord and run to a completely different plug in and put them on that same outlet. Your garage should have a GFI and see what happens after that test.

 

[OldShooter]

Change out GFI. They get weak and stressed and just won't hold the current level and trips.

This. I don't like those combination duplex outlet/GFI gadgets. Their attraction is that they are cheap. Where feasible/possible I use GFI breakers in the panels.

No real reason to BTD on an electrician though. Buy a replacement outlet at your local big box home store, turn off the breaker in the panel, and change the probably-bad one out. Pay attention to polarity. Use a tester to check the new outlet for voltage, polarity, and GFI function. (If you don't already have a tester, Klein makes a couple for about ten bucks each. https://www.kleintools.com/catalog/electrical-testers/gfci-outlet-tester A tester will also verify that the outlet is dead before you work on it. I have had good luck with Klein, especially their tools.)

 

[COcheesehead]

I could there are contacts and might be a little corrosion going on. I guess what I would do is take an extension cord and run to a completely different plug in and put them on that same outlet. Your garage should have a GFI and see what happens after that test.

There is a second outlet on the roof and it works fine. There are two separate flat roof sections and the heat tape wouldn’t stretch over parapet walls, otherwise, I would just go to plan B. It’s something specific to that outlet.

 

[COcheesehead]

This. I don't like those combination duplex outlet/GFI gadgets. Their attraction is that they are cheap. Where feasible/possible I use GFI breakers in the panels.

No real reason to BTD on an electrician though. Buy a replacement outlet at your local big box home store, turn off the breaker in the panel, and change the probably-bad one out. Pay attention to polarity. Use a tester to check the new outlet for voltage, polarity, and GFI function. (If you don't already have a tester, Klein makes a couple for about ten bucks each. https://www.kleintools.com/catalog/electrical-testers/gfci-outlet-tester A tester will also verify that the outlet is dead before you work on it. I have had good luck with Klein, especially their tools.)

I am getting beyond my pay grade here, but there is a GFI on the outlet AND there is a breaker for the circuit.
I may just run to Home Depot and change it out. It could be an electrifying experience.

 

[COcheesehead]

I just checked my local HD has a 20amp in stock in grey to match the old one. I think that will be my Friday project. I will report back.

 

[OldShooter]

I am getting beyond my pay grade here, but there is a GFI on the outlet AND there is a breaker for the circuit.
I may just run to Home Depot and change it out. It could be an electrifying experience.

Yes, that's normal wiriing. The breaker protects everything connected to it, including the GFI circuit. The GFI outlet protects only what is connected to it, either plugged in or cascaded from it. In your case there are probably no cascaded outlets but you really don't care.

Preventing "electrifying:" Pay attention to the color codes and put everything back the way you found it. A cell phone camera is handy for this. You should see a silver-colored screw with a white wire connected to it, plus a different color (brass, probably) screw with a black or red wire connected. Those are neutral and hot, respectively A green or bare wire connected to a green screw is your safety ground. Buy a tester and use it. First to check that you've switched the right breaker and the circuit is dead, then to verify that you've gotten the polarities right on reconnection and that the GFI works.

While you're at HD pick up a copy of "Wiring Simplified." Read it and become a more capable and confident home electrician.

 

[Car-Guy]

Turn off the power before changing it out (and verify it's off) and don't fall off the roof. Hate to see anther thread about another member in the hospital, or worse.

 

[COcheesehead]

Yes, that's normal wiriing. The breaker protects everything connected to it, including the GFI circuit. The GFI outlet protects only what is connected to it, either plugged in or cascaded from it. In your case there are probably no cascaded outlets but you really don't care.

Preventing "electrifying:" Pay attention to the color codes and put everything back the way you found it. A cell phone camera is handy for this. You should see a silver-colored screw with a white wire connected to it, plus a different color (brass, probably) screw with a black or red wire connected. Those are neutral and hot, respectively A green or bare wire connected to a green screw is your safety ground. Buy a tester and use it. First to check that you've switched the right breaker and the circuit is dead, then to verify that you've gotten the polarities right on reconnection and that the GFI works.

While you're at HD pick up a copy of "Wiring Simplified." Read it and become a more capable and confident home electrician.

I have switched out many dimmers and installed lighting/fans so I know a little bit. The part that gets me is when you read the instructions for three wires and then you open up the switch and there are four.

 

[COcheesehead]

Turn off the power before changing it out (and verify it's off) and don't fall off the roof. Hate to see anther thread about another member in the hospital, or worse.

The roof is flat at that point and I do have some ladder skills. Maybe I should take photos of the process. That would be exciting for everyone LOL.

 

[COcheesehead]

This is the area in question. It’s been in the 50’s here, but you can see ice stays in the shadows on the north side. It’s that way until about February.
The black cord is one of the heat tapes running down one of the downspouts.

 

[street]

I have had then go bad it seems for no reason GFI. Use the outlet one day a week later it keeps tripping. Frustrating when you got a project going.

now have a spare in the drawer when it happens. I live rural so small town so just can't run to Menards to get one when I need one.

Good Luck COCheesehead.

 

[COcheesehead]

I have had then go bad it seems for no reason GFI. Use the outlet one day a week later it keeps tripping. Frustrating when you got a project going.

now have a spare in the drawer when it happens. I live rural so small town so just can't run to Menards to get one when I need one.

Good Luck COCheesehead.

I went out and looked at it. It says to test monthly. I have those buggers all over the garage and bathrooms. I might buy a couple just to have around.

 

[COcheesehead]

I appreciate everyone’s input. Thank you.

 

[street]

The one thing you could do is take one GFI out of the garage and replace that one with the one that is causing problems. If it works than you know for sure it is GFI and not something else.

 

[COcheesehead]

The one thing you could do is take one GFI out of the garage and replace that one with the one that is causing problems. If it works than you know for sure it is GFI and not something else.

Oh, now you’re talking.