Electrical help

[JDG]

Tried to plug my MH into our house system. I have a "01 35ft Suncruiser with a 30 amp system. The 20 amp GFI that I was using kept tripping as soon as I plug it in. Has anyone had a problem using a GFI plug? If I use a non GFI plug I seem to be OK. As long as I don't run the heater or A/C.

[akadeadeye]

Originally Posted by JDG

Tried to plug my MH into our house system. I have a "01 35ft Suncruiser with a 30 amp system. The 20 amp GFI that I was using kept tripping as soon as I plug it in. Has anyone had a problem using a GFI plug? If I use a non GFI plug I seem to be OK. As long as I don't run the heater or A/C.

I had this problem once right after I had run the batteries down way too low by leaving a couple of things turned on while the MH was in for repair. When I put it back in storage, I plugged in to the 20 amp from a 30 amp dogbone to our 50 amp cord. It started bulk charging the batteries at about 14.8v. I messed around doing a few things and made a final check and discovered the GFCI had tripped. Someone told me the MH system was drawing a lot of amps trying to get the batteries charged back up.

It could have been that, but it also could be that the breaker for that plug serves several other storage units, so I don't know. I do know it hasn't happened since and I have not discharged my batteries since then either, so maybe it did have something to do with the discharged batteries.

Don

[Midniteoyl]

First thing to do is check for a wiring fault in the adapter or cord.. like the ground/neutral being swapped. I use a 20 amp GFCI to power my 30 amp rig with no problems..though, sometimes when I plug anything in, not just the motorhome, the GFCI will trip.. I hit the reset and all is good.

[wa8yxm]

A GFCI compares current in the HOT and NEUTRAL legs and if they do nto match.... CLICK of Safety.... Many motor homes have a lot of electronics in them and many of these devices have devices in them to bypass what is called "Power line noise" to ground... One of two of these devices (Capicators) will not trip a GFCI but by the time you add all the "Stuff" with them in a motor home up you can get a significant leakage current.

Second many motor homes have Inverters and sometimes they bond neutral and ground on the inverter.... (Need not be done normally)

And some converters will tend to bond the neutral to ground epically if the batteries are either low or full (Depending on the inverter)

All in all.. that trips the GFCI.

You do need to track it down though because SOME of the things that can do it are dangerous... For example a short in the fridge electric heat element or the water heater electric element.

[Engineer Guy]

The State Code Inspector told me, though 'legal', he does not favor connecting GFIs in series. One such example would be having a Circuit Breaker GFI in the Main House Box, and a subsequent Outlet GFI in a Kitchen, Bath or Garage Circuit. Each GFI is measuring for very small, non-balanced currents and presuming there's leakage to 'somewhere' - possibly via a Human Body - before they trip quickly. Even with no such leakage occurring, GFIs trip problematically, he says. This could be what your experiencing, besides the excellent explanations above.

[timmer594]

Same problem here. Even with all breakers open gfi trips. I will troubleshoot cord soon. Read somewhere its because gfi in MH causes it. But that doesnt compite if breakers open.

[ksg5000]

Is this an issue that also arises when your hooked up to std 30 amp shore power at a campground?

You might consider just replacing the GFI - I am no electric guru but over the yrs I have found that older GFI get flaky and it doesn't cost much to buy a new one.

[vermilye]

Same problem here. Even with all breakers open gfi trips. I will troubleshoot cord soon

A long, but possibly useful answer -

If a GFCI trips when all the breakers are off you have a ground/neutral fault. Although all GFCI breakers or receptacles detect differences between hot & neutral current, modern ones also detect faults between the neutral & ground.

These are hard to find since you can't use the circuit breakers to isolate the problem circuit. Typical problems that cause this are bad heater elements in either the refer or hot water heater, moisture in a receptacle, or an actual short between the ground and neutral wiring, either by a failure in a wiring box, a screw penetrating the wiring, the failure of an isolation relay in a inverter, a bad converter, or mistakenly tying the ground & neutral together.

In any case, finding the problem involves more digging into things than most non-electricians are willing to (or maybe should) do.

If you want to find the problem, be sure all power is off including generator & inverters, unplug the shore power, open the RV's breaker panel, shut off all circuit breakers & disconnect one of the neutrals (white wires). Plug the RV's power cord into a GFCI protected receptacle. If it trips, that circuit is not the problem. Reconnect it and try another one. If you go through all of the neutrals without finding the problem, it fault must be in the supply cord.

It is more likely you will find the circuit causing the problem. Follow the bad neutral to where it enters the breaker panel, identify the associated hot (black) wire & follow it to the breaker. That will identify which circuit is causing the fault.

Look for what is causing the ground/neutral fault. If it is your water heater or refer, it is likely a bad element, particularly if you might have fired up the water heater on AC without water (it may still work, but the over heating causes the element cover to fail, allowing water to reach the heater wires).

If it is the converter, it needs to be replaced. Some older models will cause this problem. If it is a standard receptacle circuit, look for touching wiring or moisture. Be sure nothing is plugged into the chain of receptacles - appliances can develop faults.

Again, the problem with a ground/neutral fault is the RV will work fine plugged into a 30 amp receptacle, or a non-GFCI 15/20 amp receptacle, but is is unsafe. If your ground connection fails, the neutral/ground fault could make the chassis hot to the earth, shocking someone touching the RV.

An RV should be capable of operating plugged into a GFCI receptacle. If it can't, something is wrong & should be fixed.

[Bug512]

Not doubting that there may be a problem with the original posters motohome.

My question is how would you know if you had a problem if you never plug into a 15 or 20 amp GFCI?

For example, we never have plugged into a 15 or 20 amp GFCI. We have both a 30 and 50 amp receptacle at home. I have never seen a 30 or 50 amp GFCI.

[Midniteoyl]

usually used for Hot Tubs/Pools.. 50 amp GFCI. - Cerca con Google

[vermilye]

Not doubting that there may be a problem with the original posters motohome.

My question is how would you know if you had a problem if you never plug into a 15 or 20 amp GFCI?

For example, we never have plugged into a 15 or 20 amp GFCI. We have both a 30 and 50 amp receptacle at home. I have never seen a 30 or 50 amp GFCI.
__________________

You won't.

[wa8yxm]

Originally Posted by timmer594

Same problem here. Even with all breakers open gfi trips. I will troubleshoot cord soon. Read somewhere its because gfi in MH causes it. But that doesnt compite if breakers open.

I have often plugged GFCI devices into GFCI outlets (That is there was a 2nd GFCI in series) I have never had one GFCI cause another to trip.. though I have had cases where they both tripped (Kind of rare, usually one goes first)

I agree "This does not compute"

NOTE: Moisture can and does get in plugs, even the molded on ones, and ... Well, that often trips GFCI's

[Midniteoyl]

GFCI's in series will cause problems... Is that the case here? prolly not since he turned off all the breakers..

[Dsouthw524]

Before going too far! Check if the problem is the particular GFCI by running a cord to a different circuit with a GFCI. As mentioned earlier, the GFCI can go bad over time or fatigue.

Start with the basics first!

[Engineer Guy]

Way back in my Tech Support days, I informally taught 'Troubleshooting 101'. It's the rigorous application of 'Cause & Effect' by looking at 1 - and only 1 - possible variable at a time w/o guesswork like 'it can't be that'.

Safety first, so this needs to be done w/o distraction; cutting corners; Kids or Pets around, etc.. Until the Rig Breakers are exonerated, there will be lots of trips back-and-forth to shut A.C. Box Power off. One Industrial trick is to hang something non-conductive in front of where you're working as a reminder when the main power is back on. Remove it when the power is off, and so on.

Job 1: see if another Box GFI trips while a <15 Amp Load is drawn by your Rig. If so, follow the cable into your Rig. Snap loose one end of the Breakers [the upper end] to take them out of the Circuit and see if the problematic GFI still trips. Snap 1 Breaker back in and reenergize them one at a time. Disconnect the Converter/Inverter. And so on. By having only 1 item connected at a time, the GFI-tripping leakage source will reveal itself. It might be obvious as the Nose on your Face, or it might be a really-rare problem.

I once had a Rental flooding emergency [someone else's Property, fortunately]. Turns out a Drywall Screw was driven through a Water Pipe during construction. The dissimilar metals in the Screw and the Copper Pipe meant the fault degraded over the years. One day - boom - a flood at City Water Pressure w/o warning.

The point: a similar, very old and weird problem could now have surfaced in your Rig. Only the 'baby steps' of rigorous Troubleshooting w/o any assumptions will reveal such unsuspected problems [on the Water Heater Circuit, and so on]. One of several sharp suggestions above mentions the possible Factory bonding of Neutral to Ground. This is supposed to occur once, and only once, in either the House Breaker Box, or the Campground Breaker Box; not at 2 places simultaneously [Rig and external Box]. Case-in-point, this might have been 'ok' for years, but have arisen as a problem only now. And so on...

Have a pal help if you're not comfortable around exposed House voltage. A Voltmeter; thin flexible Gloves; insulated Shoes; and never resting a Hand anywhere simultaneously where voltage can pass through your Heart are old tricks used by us 'Sparkies'.

[JDG]

This is the exact same situation. I went to get my MH from the storage lot and the main battery was dead. Had it jumped drove it home and tried to plug in to our outlet and it popped the GFI. Now after fully charging the battery I will try to plug it back into the GFI.
Thanks for the info.

[Engineer Guy]

A bit of forgotten trivia popped into my Head...

To keep some Plumbing to some tall, slender Cisterns in our Mountain House Garage from freezing, I put on some Heat Tape. Even though the dedicated Outlet was >3' off the Floor, I put in a new 15 Amp GFI, thinking protection by water was all good. A pal who built nearby found the GFI tripped one Winter when checking on our House. For the record, the unmodified Heat Tape drew much less than 15 Amps.

The Electrician for my pal's new House nearby said authoritatively that they don't install GFIs where Heat Tape is used, due to 'false' tripping. I don't know what the technical Root Cause for this observation is. Inrush current? Occasional Storm-caused A.C. surges? Most all Kitchens have GFIs, due to Outlets near Sinks & water, yet Toaster Ovens and other Appliances work fine in my experience.

An interesting bit of Detective work would be to plug in a Rig with discharged Batteries and/or a tank of cold Water to be heated electrically [per the very informative Post above]. If the same GFI trips initially, but doesn't trip after the Batteries are charged and/or the Water is heated, that's a huge clue to be chased down methodically. In an ideal World, this same test would be repeated while connected to a non-GFI Outlet to make absolutely sure the problem is not inrush current draw near/above the trip limit of a Circuit Breaker.

[Midniteoyl]

I know GFCI's are used on resistive and inductive loads so why yours would trip? Dunno.. bad tape? Im thinking the heat tape has too much 'leakage'..

[Engineer Guy]

Midniteoyl ~ This was a weird one, with the final analysis taken on Blind Faith [not my style!]. In that the Electrician who rendered this opinion did a lot of work in the Mountains, but had not seen my sparkling new Heat Tape install, we had to deduce it was some issue - as you guess - endemic to Heat Tape. Plus, it's a VERY random problem; from never tripping to 1x/yr. It didn't even come up as a problem until after several years of Winter-only, leak-free Heat Tape use.

This ex-Ham/Electronic Geek 'Sparkie' has seen a lot of weird ones, but I'll have to remember to ask an Electrical Contracting pal what's he seen on this topic. No moisture was ever around, and the Heat Tape never even touches Ground; the Floor, or anything to represent a leakage path. It was my usual clean, dry, A-R install... This same pristine condition of the surrounding environment made me comfy to return to a non-GFI Outlet. Nothing succeeds like success...

[Midniteoyl]

I saying to much leakage in the tape itself.. the GFCI is detecting a short.