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Ground fault alarm

Jetstreamer
Explorer
Explorer
We're plugged into 50 amp shore power at a campground and my little plug-into-the-wall-outlet electrical monitor will occasionally ( not continuously) alarm a ground fault condition. Freqs and voltage are steady. What is happening and how concerned should I be?
5 REPLIES 5

Wayne_Dohnal
Explorer
Explorer
The TRC web site is pretty short on details. There is one mention of testing for "open ground" so I'll assume that's the type of ground fault it's reporting. It's not possible for the tester to directly test for an open ground, so some other thing or things are monitored and interpreted, and one of those interpretations is open ground, and it's usually correct but could be wrong. For instance, the tester could interpret a few volts difference between the ground and neutral wires as an open ground. But if there's a long wire run from the point where the neutral is actually grounded, there could legitimately be a few volts difference. The varying load presented by your rig and other rigs could send the neutral voltage back and forth over the threshold where a fault is declared. After saying all that, the short version is that maybe there's a real problem with the ground wire, and maybe there isn't. It would take probing with a meter to make a better diagnosis.
2009 Fleetwood Icon 24A
Honda Fit dinghy with US Gear brake system
LinkPro battery monitor - EU2000i generator

Jetstreamer
Explorer
Explorer
It's a TRC digital monitor that just plugs into an outlet. A digital display shuttles between volts and frequency and will generate a beep if it sees a problem with wire diagnostics. It wasn't a cheap unit. I use it frequently to check campground power and this is the first time I have seen an intermittent ground fault alert. It's pretty much the same alert that an ungrounded generator would produce. From what it says on the top of the unit, the fault generated is "open ground fault connection".
I guess my assumption is a bad possibly intermittent ground inside the pedastal.

Wayne_Dohnal
Explorer
Explorer
It would help if you post what kind of monitor you're using. There are two pretty opposite situations that could be considered a ground fault and at least I don't have a clue which one your monitor is indicating.
2009 Fleetwood Icon 24A
Honda Fit dinghy with US Gear brake system
LinkPro battery monitor - EU2000i generator

Mandalay_Parr
Explorer
Explorer
I would check all electrical connections in your power distribution panel. Make sure they are all tight.
Jerry Parr
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Harvard
Explorer
Explorer
If your GROUND conductor was OPEN and you were getting an intermittent but fairly steady GROUND PATH through the landing gear. OR, the RV plug GROUND conductor CONNECTION were intermittent. etc etc