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Line outlet tests okay but upstream outlet shows open ground

Line outlet tests okay but upstream outlet shows open ground

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Old 01-06-19, 02:08 PM
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Line outlet tests okay but upstream outlet shows open ground

I've had a GFCI breaker tripping intermittently for quite a while and am trying to determine the cause. I think i may have resolved that today but during troubleshooting I found a situation I don't quite understand. I have an outlet (load) that powers a downstream switch which then powers a downstream outlet. The load outlet (1st in the series) tests showing open ground. The hot runs from there to the switch with the switch continuing the hot to the end point outlet. The neutral is carried to the end point outlet by wire nutting a pigtail from the end point (line) outlet to the load neutral in the switch box. The ground wires are all wire nutted together in the switch box (it's a little crowded in there!). What weirds me out is that the last outlet in the series tests good with my plug-in tester but the first switch in this series shows an open ground. I can't figure out how the last outlet's ground is good but the one upstream is not. I've used 2 different testers. I'd sure appreciate someone helping me understand what might be going on with this and what the next steps might be to resolve it.

Thnx,
Jag
 
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Old 01-06-19, 02:18 PM
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Pictures of both would be helpful.
 
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Old 01-06-19, 02:44 PM
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I think you are confusing terms.

Something connected to the line side of the GFI is not protected or controlled by the GFI.
You'd need something connected to the load side of the GFI to cause it to trip.
Those testers typically show open ground when the neutral is missing.
How-to-insert-pictures
 
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Old 01-06-19, 02:55 PM
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Thanx PJ. It is quite possible that I'm confusing terms. I should say that this entire circuit is protected by a GFI circuit breaker. There's only 4 outlets and a switch on this circuit from what i've been able to determine. There's virtually no load on 3 of them with one carrying the load for the central AC/heater. I found in one of the boxes (an outdoor outlet) where it appeared the hot had been arcing to the metal box. I've removed that outlet and capped the hot and neutral to see if that resolves my tripping problem. I can take pictures at some point but i have it all back together now and i don't seem me getting back into it today or likely this week. It just doesn't make sense to me.
 
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Old 01-06-19, 06:25 PM
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I found in one of the boxes (an outdoor outlet) where it appeared the hot had been arcing to the metal box.

It's no mystery, that would definitely trip a GFCI breaker.

What weirds me out is that the last outlet in the series tests good with my plug-in tester but the first switch in this series shows an open ground.

How are you testing for ground at the first switch?
 
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Old 01-07-19, 02:54 PM
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Joe - definately would trip the breaker. That's what I was referring to when I said I thought I'd found the problem. The real question had to do with the open ground question. I apparently screwed up my terms again when i said the first "switch". I meant to say recepticle. For lack of a picture, the wiring comes into the closet from the attic area, through the top plate and proceeds downward to the "first" outlet (tests to open ground), then to a switch which controls the outlet below which is the end of the run. This last outlet tests good. I'm using a plug-in 3-wire recepticle tester for the outlets.
 
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Old 01-07-19, 03:44 PM
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Ok...... if your test shows open ground at the first box the circuit appears at..... that's where the problem is. It's pretty hard to be open at the first box and then normal at the others.

Those plug in testers are hard to understand. They can/will show various things with an open neutral. It's best to troubleshoot a problem like this with a meter. Even a basic $15 analog meter from one of the home improvement stores will work.
 
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Old 01-07-19, 05:23 PM
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Thanks PJ. Next warm spell we get I'll try and get into it. Figures it would be that one - it's a PitA to get into. I do have a meter - just takin' the easy way out. I almost hate to cut the power to it now. It's been up since I capped the wires, but I want to get the open ground resolved. Thanks again!

Jag
 
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Old 01-07-19, 06:12 PM
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Checked with the meter. It looks as though it's wired in reverse. Add this to my to-do list! Thanks all!!
 
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