shore power trips GFIC

[rdhoyum]

I been searching and trying several things to correct this problem:

When plugging in shore power line (30 amp) to a standard 15 amp outlet, using short adapter cord, the GFIC trips immediately. However, when plugging in shore line to a 30 amp outlet, no tripping of circuit. This occurs at storage, at home and at rv parks.

The resulting problem is I can't keep batteries charged or have power when in storage.

I have found no GFIC outlets in the AS. It's a 98 Excella 1000. Been ours for 5 months and always happened. I have unplugged converter, still happens. Unplugged frig, still happens.
Checked shore cord, no damage. Checked wiring of shore cord plug, all is correct.

Electrical is the only area I have limited knowledge and the one area I choose not to make mistakes.

Any ideas? things to check/test?

[Dan@LED4RV]

You have done pretty good on eliminating some things. I would pull the breakers one at a time to see if you can see which circuit the problem is on. If that tells you something then try to figure which where that circuit runs (inside the unit) and go to the farthest 110 receptacle and see if you can find a problem.

[richinny]

like dan said, if all the breakers are off and it still trips then inspect the power cord(s) including just plugging in the adapter. you should have a GFCI breaker in the main panel.

[idroba]

If your hot water heater is gas and electric, try unplugging the electric part. It is common to have an element failure which leaks enough current to trip out a GFI.

A 30 amp campground outlet is not GFI protected, so you would not see it happen there.

[TG Twinkie]

Check to see that the ground and neutral busses in the trailer are not bonded together. Also check to make sure the hot leg and neutral are not reversed. There are plug in devices available to test for bad grounds and reversed wiring. You can find them at big box and hardware stores. Some modern converters will cause GFI tripping as well.
Are there other devices connected to the GFI circuit you are plugging into? You may be overloading the 15 amp circuit if this is the case.

[reo]

Could it possibly be a defective 15 to 30 amp adapter?

[Protagonist]

Originally Posted by rdhoyum

When plugging in shore power line (30 amp) to a standard 15 amp outlet, using short adapter cord, the GFIC trips immediately. However, when plugging in shore line to a 30 amp outlet, no tripping of circuit. This occurs at storage, at home and at rv parks.

One thing to keep in mind is that when you hook up using a 15-amp-to-30-amp adapter, you're only providing 15 amps to your trailer, not 30. The adapter just lets you go from one type of plug to another; it does not double the amperage coming out of the 15-amp socket.

Not sure what appliances you're running concurrently on your 15-amp supply, but the most likely culprit for tripping the breaker is that you're overloading the circuit, trying to draw more power than there is available.

It probably has nothing to do with a ground fault; a GFCI breaker is still a breaker, and will trip normally the same way a non-GFCI does if you try to run too many appliances at once. If it was a ground fault, it would trip when you're plugged into 30-amp service as well.

[rdhoyum]

First off, Thanks for the help guys!
I'm pretty sure I've tried another 15-30 adapter, but that will be first thing I do.

There is a GFI breaker in the box and it has only tripped with several high wattage items in use. I haven't pull each breaker yet, but that will help to isolate the problem.

Water heater is gas only. I have updated the converter with an IOTA DLS-55. There are two grounds attached to the unit. One is stranded and the other solid copper. I'd believe that to indicate both 12 volt and 120 volt????? Should they both be connected there? I'll get the testing devices to help out.

I thought the storage space power outlet may have been overloaded...with several others plugged in!!!...but then it happened at home on the RV dedicated outlet. I tested the overload theory by unplugging the others at storage and it still tripped immediately upon plugging in. I'm sure it's trouble in my unit.

I too concluded it probably isn't a ground fault somewhere, since the 30 amp circuit doesn't trip using the shore cord without adapter. Would the 30 amp outlet really not trip the breaker with a ground fault???

As you can see, I'm stumped on this one. I'll be bringing it home in a few days for a week-long trip close to home. So I'll try some things and get back with a post.

Thanks again.

[TG Twinkie]

The 30 amp breaker would trip if it is either overloaded or there is a short between the hot leg and neutral or ground. A GFI breaker is measuring the current between the hot leg and the neutral, if they are out of balance by a slight amount the breaker will trip.
The DC common is routinely referred to as Ground. When used in an application like your trailer the DC common is attached to the skin and/or frame of the trailer. Just as it is on your TV. It simply saves in the amount of wire used since you only have to run one wire to provide power to a DC device then connect the other wire to the skin of the trailer. For example, the water pump in the trailer has 2 wires, one Red and one Black. You would connect the Red wire of the pump to the +12 volt wire from the switch then connect the Black wire of the pump to the skin of the trailer giving you the negative side of the 12 volt power.
The AC 120 volt system has 3 components. The hot leg, the neutral and the ground.
The ground circuit is a SAFETY function. When connected correctly to the trailer it is also connected to the frame and/or skin. The AC ground provides a means of safety in that it takes any current to earth ground, therefore preventing electrocution. Without the earth ground if a hot wire or open neutral wire would come in contact with the skin/frame there would be 120 volts on the outside skin. If you touched the skin in this case while standing on the ground outside, you would get shocked.
Both the DC common/ground and the AC earth ground are connected to the skin/frame of the trailer.
The AC 120 volt neutral should NOT be connect to the skin/frame of the trailer. The most common method is to use a bonding screw on the neutral buss which connects the buss to the metal wall of the power panel. If there is a bonding screw in the neutral buss, it should be removed. The neutral plane in the trailer floats, in other words it is not connected to earth ground.

[idroba]

Originally Posted by rdhoyum

(snip)

I too concluded it probably isn't a ground fault somewhere, since the 30 amp circuit doesn't trip using the shore cord without adapter. Would the 30 amp outlet really not trip the breaker with a ground fault???

Thanks again.

If you do not use an adaptor, and plug directly into an RV stile 30 amp outlet as in a campground, you will not trip a GFI as the 30 and 50 amp outlets in RV parks are not required to be GFI protected, only the 20 amp ones. If you Dedicated home RV outlet is a normal 20 amp outlet and it is a GFI outlet or is on a GFI breaker (and it sounds like it is) you may have a ground fault in your trailer somewhere and it should be found and repaired. It only needs to be a very small leak of 5 mA to cause the GFI to trip.

So, is you home outlet a 20 amp one protected by a GFI and that is what is tripping out? And when you plug into a 30 amp outlet in a campground you have no problem? If so, repeating myself, the 30 amp outlet is not GFI protected, and the 20 amp one is. You will need to work on it and find the small leakage that is causing the issue.

[rdhoyum]

Originally Posted by richinny

like dan said, if all the breakers are off and it still trips then inspect the power cord(s) including just plugging in the adapter. you should have a GFCI breaker in the main panel.

I did find the GFCI breaker in the main panel. It's one of four breakers, one being a double pole. Now the GFCI is the AC circuit. Is that the normal or should the GFCI be the main breaker???

I discovered the AC causes the shore line outlet to trip. While sealing a small leak, the control switch plug was disconnected. While the breakers were all installed and nothing had tripped, I re-connected the AC controls and that tripped the shore line immediately.

I've had AC working just fine when using the 30 amp shore line plugged in direct to a 30 amp outlet. Anyone have suggestions on what to check on AC or how to change around the breakers as they should be.?

[TG Twinkie]

If your supply voltage is thru a 15 amp breaker it will trip when you try to run the AC. You need a minimum of 20 amps to run the AC. If you are running more than just the AC you will need the 30 amp service.
The 15 to 30 amp adaptor is not sufficient to run the AC, you will damage the motors in the AC unit because of the voltage drop.
The starting current for the AC will trip a 15 amp breaker.
I don't know if your trailer is wired with a main breaker. If you post pics we may be able to determine what you have.

[richinny]

in my '94 34' as stated above, the 20A breaker controlled the microwave/air conditioner via the either/or switch in the overhead cabinet.

if you only have one gfci in there it was for the bath, galley, refrigerator and outside outlet in my '94.

if it trips without having the ac unit running i think it would be a wiring issue. there is a thread on a similar issue i'll try to find.

[richinny]

this thread may have your answer. if you don't want to read all the interesting posts the answer is in post #40 :-)

http://www.airforums.com/forums/f37/...lks-21082.html

[rdhoyum]

After some delay, I was able to correct this with the tips I got from this posted and the linked post provided. Thanks again to all.

It was the storage yard's power outlet that was tripping everytime I plugged shore line cord in...using the 30/15 adapter. I removed the small round ground prong from the adapter, everything works just fine.

[Protagonist]

Originally Posted by rdhoyum

I removed the small round ground prong from the adapter, everything works just fine.

Expedient, and probably the best you can do without rewiring some one else's electrical system. But not necessarily the safest thing you could have done, if any of your electrical systems develop a fault while you're plugged in.

I'd also suggest you buy another adaptor, and don't remove the ground prong, for the next time you have a chance to plug into a properly wired outlet.

[ghvoelker]

Just read this. Holy Cow!!!!! The GFCI is telling you you have a fault!!!!! Never, clip the ground prong!!!! It is there for a reason!!!!! The advice has beeen given that this is probably caused by the neutral and ground being connected in the trailer. Curing the problem by clipping the ground prong is demonstrating that that is most probably the case. I had the exact same problem. The trailer had been repaired by a PO after crunching the rear corner. The breaker box was behind that panel. When it was rewired, the neutral and ground were bonded together. That works in your house but not in the AS. The system sees it as an appliance. I found the problem just as you did by plugging into a 15 amp GFCI outlet. There was never a problem with the 30 amp shore power because they had no GFCI protection. I wired the panel correctly and it cured the problem.

Eric

[idroba]

By removing the ground pin on your adaptor you did not fix the problem, only hid it. Please find the real problem of leakage somewhere in your trailer so you don't become the ground path one day when you open your door.