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]

Quote:

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]

Quote:

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]

Quote:

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]

Quote:

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!