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Old 03-30-2018, 02:59 AM   #1
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Open ground in rv 110 outlets

I was testing my outlets in our VEGAS and the tester indicates OPEN GROUND. This is on shore power as well as generator.

Shore power external surge protector shows good ground.

I am assuming issue is probably either transfer switch or electrical panel.

Has anyone else had this issue?

If so, what was the "fix"?
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Old 03-30-2018, 01:12 PM   #2
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Sounds like a unique trouble. I would start by going to your GFCI outlet and push the test button and see if it trips. If it does , then the ground is good to there. Otherwise it's open back toward the transfer switch.
Good luck.
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Old 03-30-2018, 01:18 PM   #3
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This will require physical inspection of the wiring. For safety don't do this while on shore power or the ginney is running. I'd start at the transfer switch although I would not expect it to switch the ground. The ground wires should be either green or bare copper. White is neutral and black is the hot wire.
Let us know what you find.
Our's has a common neutral buss near the water heater. Haven't looked at the transfer switch, but then we haven't had this problem.
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Old 03-30-2018, 05:45 PM   #4
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Originally Posted by scrubjaysnest View Post
This will require physical inspection of the wiring. For safety don't do this while on shore power or the ginney is running. I'd start at the transfer switch although I would not expect it to switch the ground. The ground wires should be either green or bare copper. White is neutral and black is the hot wire.
Let us know what you find.
Our's has a common neutral buss near the water heater. Haven't looked at the transfer switch, but then we haven't had this problem.
Ok, so take all the drawers out, take the cover off the transfer switch and test the continuity on all the grounds: ALL GOOD. Test between the transfer GROUND and the GROUND from the breaker box: ALL GOOD. Test the ground connection to the outlet for the outside TV to Breaker Box GROUND: ALL GOOD. Test the ground on a GFI outlet: ALL GOOD.

Scratch my head, then it hits me, maybe the receptacle tester is bad...Get a NEW tester (fresh out of box) ALL GOOD. Try the other tester, shows OPEN GROUND. Guessing that the lamp on the GROUND indicator is burnt out. Well, at least, everytime I go crawling around the underbelly of our VEGAS I learn more about things....

Thanks for you guys being around for "moral support"...
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Old 03-31-2018, 02:30 PM   #5
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Quote:
Originally Posted by Mo_Mike View Post
I was testing my outlets in our VEGAS and the tester indicates OPEN GROUND. This is on shore power as well as generator.

Shore power external surge protector shows good ground.

I am assuming issue is probably either transfer switch or electrical panel.

Has anyone else had this issue?

If so, what was the "fix"?

Just curious, when you say open ground per testing youíve done, are you saying that your ground and neutral are not connected together in motorhome?

If you tested motorhome just parked with nothing running or shore power connected, is neutral leg grounded?

I realize you found issue with tester, but your test results could help me clarify a problem Iíve had before.
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Old 03-31-2018, 04:17 PM   #6
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I had tested with one of those plug in testers that have two yellow lamps and one red lamp. The lamps that are illuminated show what the status of the "plug" is. Two LIT YELLOW lamps show "correct", one center LIT YELLOW lamp shows "open ground". So on my defective tester (with apparently one yellow lamp not working) it appears I had an "open ground"

So, since I assumed that I had an open ground, I grabbed my trusty VOM meter and started testing resistance on my ground leads. I didn't actually go into the breaker panel, put tested the ground wires coming from shore power, the generator, the breaker box, and several receptacles which showed all ground wires were connected.

The ground wires from the transfer switch and the breaker box disappeared under the RV and apparently onto the common ground for the rv.

Does that help at all?
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Old 03-31-2018, 06:08 PM   #7
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Originally Posted by Chance View Post
Just curious, when you say open ground per testing youíve done, are you saying that your ground and neutral are not connected together in motorhome?

If you tested motorhome just parked with nothing running or shore power connected, is neutral leg grounded?

I realize you found issue with tester, but your test results could help me clarify a problem Iíve had before.
My expectations... not necessarily reality... and I didn't check on my coach... so the opinion is worth what you paid for it!

It depends on the 'default state' of the transfer switch... which I think is shore power - as it takes time for the genny to stabilize and be brought 'online' when starting...

Using that ASSUMPTION, I would expect with nothing connected that neutral and ground are NOT bonded - and will show as open between them... The RV is technically a 'subpanel' to the shore power - and should rely on the bonding of neutral and ground outside the RV...

If the transfer switch is toward the genny - then the genny would provide the neutral/ground bonding and neutral would show as grounded...

Does that make sense to what you are seeing?
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Old 03-31-2018, 08:32 PM   #8
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Thanks guys, information helps confirm what I expected.

I was relating this data to a conversation I had with an electrical engineer who thinks improper grounding is the main reason some RVs canít be plugged into GFI-protected outlets without tripping them. Thanks again.
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