50A 240V GFI Circuit Breaker Tripping with nothing connected to it

[sms]

My pool pump has sub-panel with a 50A 240V GFI Circuit Breaker.

It was not coming on this morning.

First

----- The breaker, which also has a GFI, wasn't tripping but I measured no voltage at the load side.

I looked at the pump wiring which was all fine.

If I pushed the Test button then the breaker tripped.

A little later

-------------- I did nothing, but then the breaker would not trip even pushing the Test button. Still no output on the load side. The load was still connected.

A little later

------------- The breaker would trip immediately even with the load disconnected completely.

Fourth

------ I bypassed the breaker temporarily and the pump comes on (there is still another breaker at the main panel but not a GFI breaker so it was okay for a few seconds).

So I wonder if this is just a bad breaker or if I'm missing something. It's over $100 for a replacement. I ordered one because I can't imagine what else it could be since it trips with no load connected.

This is the breaker:

Couldn't find one in the SF Bay Area at any price, but I found a supplier in Sacramento for $102 plus tax and shipping.

I was thinking of putting in a fuse block temporarily with two 50A fuses while waiting for the new breaker. There would be no GFI protection but it's no big deal for now. We are not using the pool and no one touches the equipment but me.

[trader_4]

If by tripping when the load is disconnected you mean what I think you mean, which is you've unhooked the two hot wires from the breaker, then yes the breaker is bad. Only other possible thing there is this GFCI breaker has a connection to the neutral. Did you verify that's tight? Doubt that would account for the behavior though.

[Pat]

I just replaced a bad GFI outlet that was in an outdoor fixture. It would trip within a second even with no load connected. When I got it back inside to look at it, I could see it was full of whispy white spider webs. Every hole (3 per outlet) plus the holes on the back where the wires attach were white.

[sms]

Since I needed the pump running right away (I just put in phosphate remover yesterday and it needs to be filtered out) I ran out and found a

240V 20A breaker at the surplus store for $3.25. No GFI but it'll be okay until the GFI breaker arrives tomorrow or Monday. The breaker for the pool pump at the main panel is only 20A anyway so the 50A GFI at the sub-panel was a little over-kill. Pump is running and I didn't get any shocks.

This is not an outlet with any real openings for anything to get into but I guess after ten years the GFI circuit failed in some way.

[John G]

I don't know your exact situation, but you may not need the 50 amp breaker to be a GFCI. You can put in a regular breaker and change the load breakers to GFCI or change the outlet(s) to GFCI.

It's possible that the insulation on the wire is breaking down and moisture is causing a ground fault. My guess though is a bad GFCI breaker.

John Grabowski

[Robert Green]

That's quite a jump, then to $104 plus S&T. I wonder what makes them so expensive?

I hope you are going to do a post-mortem, Dr. Scharf? I would be curious if there was any visible damage inside the case or infestation or water damage. We anxiously await the results.

I am betting the cause is critters (like Pat reported) or corrosion from condensation. Sometimes it's both. The GFI circuitry runs hotter than a passive or semi-passive safety device. I have found insect spoor inside of outdoor CCTV bullet cams with superfine threads and "O" ring seals. They still got in somehow, probably at the cord grommet.

Anxiously awaiting the autopsy.

I only bring this up because I recently promised my wife that I would no longer save things for parts or break them down for spare parts. I retained the right (-: to take things apart to see if they can be repaired or to analyze why they failed.

I just scrapped an APC UPS and I mostly complied. Only saved the cord, the breaker, the big transformer and the metal copper strips that make up the outlets. Bypassed juicy components that needed desoldering and testing. Saved all the heavy wires with crimped and insulated ends.

There was a time I would have desoldered even the LEDs. Arthritis took care of that. )-:

[Jerry.Tan]

When I was young, I used to do that with junked electonics, like old TVs. I save all the parts. Spend hours removing them. I still have containers full of those old parts, mostly all are from the tube era. I'll probably never use any of them.!!!

[Jerry.Tan]

Is this breaker indoors or outdoors? I find plain GFI outlets dont last long outdoors, even if they are well protected. I guess moisture still gets inside.

I agree, the breaker is bad.

[clare]

Don't be terribly surpriaed if the new one trips too. My bet is on moisture in the cable somewhere causing a very small ground current to flow - tripping the GFCI as it should.

[Jerry.Tan]

He said he disconnected the wires.....

[Jerry.Tan]

He said he disconnected the wires.....

[clare]

If he removed the load wires right at the GFCI breaker, it pretty well eliminates wiring issues. If he just disconnected the pump, there are still wires involved. Not always accurately described.

[trader_4]

More often not accurately read by some folks....

[Robert Green]

There's great variability in the quality of outside electrical boxes. HD sells a blister packed outlet kit with lots of foam inserts and even a tube of sealant. When the outlet flaps are closed the units are pretty well sealed.

I do recall on a couple of occasions when the weather conditions were just right that condensation would form inside the outlet box and in gear like CCTV cameras. It wouldn't take many cycles of that to cause corrosion troubles.

[sms]

I removed the wires at the breaker. The breaker still tripped instantly. And prior to that, the breaker would not trip and the circuit was still open so clearly it's at least part of the problem.

It's only about 15" of wire from the breaker to the timer and another 3' down to the pump so it's easy to replace all that wire if moisture is the issue.

I'll know tonight. The breaker is on the UPS truck for delivery.

[sms]

Don't be terribly surpriaed if the new one trips too. My bet is on

No wires are connected to it on the load side.

[trader_4]

Do you see many 50A GFCI "outlets"?

[sms]

You lose the bet.

I drilled out the rivets and opened it. Nothing corroded inside. No spiders or ants or anything like that.

There were a couple of fried components on the GFI PCB but I'm pretty sure I did that when I jumpered across the GFI breaker from the bus bar to the load to see if the pump was working. The reason I think the fried components happened then is that I smelled them burning when I jumpeered from the bus bar to the load.

There breakers are designed for outdoor use and they go inside a panel box designed for the outdoors, so critters would have a tough time getting in. It's very different than a GFI outlet. And outdoor GFI outlets should be in a box with those spring-loaded covers that have gaskets on them.

It is quite a complex breaker with all the mechanical and electrical pieces inside. Springs flew out when I opened it. Not surprising how much it sells for since it probably cost $20 to make, and wholesales for $50 and retails for about $100. The $102 I paid was actually somewhat of a bargain. Home Depot sells them online for $171, and a place in San Francisco wanted to order me one for $150. I'll willingly pay a little more to buy an in stock product from a local retailer, but I have no interested in paying more when they are just going to order it and I have to wait anyway.

One amusing thing is that when I was looking for one locally I looked up companies that specialize in breakers. There were four. But calling all four I found that there were really only two, they just had multiple business names with multiple phone numbers but the calls went to the same place.

[sms]

New one arrived a few minutes ago. Put it in. Works fine.

[Pat]

Great! Thanks for posting the update. If you have time, take the old one apart and see if it looks infested by bugs, corroded, or just bad for no obvious reason.

Pat