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shore power problem

March 10, 2012, 03:02:40 pm

I am connected to shore power. When I try to plug in an electric heater, after a few minutes it turns off the prosine inverter, and all the 120 is unavailable. And even the 12 volt is now unavailable. I don't know what I am doing wrong. I checked the breakers in the box right under the end of the bed. They seem to be okay. Is there a breaker or fuse somewhere else I don't know about?

I read on this forum that I should be able to use shore power without the prosine. But that is not working for me either. The Blue sky shows that my batteries are being charged, and holding nicely.

1990 36 foot

Thanks for your ideas in advance....

(I just ordered a book on RV electrical systems.... but thought you all might be able to help me before it arrives....)

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Re: shore power problem

Reply #1 – March 10, 2012, 03:22:52 pm

Check the GCFI. It is usually disguised as part of the electric outlet near the sink in the bathroom. The heater may have an electric leak to ground that is tripping the GFCI.

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Re: shore power problem

Reply #2 – March 10, 2012, 03:24:09 pm

Does your coach have a GFCI ? It should be in the bath.  Try resetting that.
I would go to the source at the pedestal and verify that you have 120V or 120 V on each leg if you are on 50 AMP.  If V OK there check  voltage at the inside breaker panel. If voltage there then check for tripped breaker and/or tripped GCFI.
It is possible that you are trying to operate a heater on a GCFI protected circuit and it is tripping out.
For a real simple check take the heater out to the pedestal and using an adapter to 120 plug it in.  If it works there then check down stream.
Good Luck
Let us know hat you find and we will try to help you further.
This situation calls for having a good quality Volt Ohm Meter and reading up on how to use it to trace out problems.
Gary B

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Re: shore power problem

Reply #3 – March 10, 2012, 03:30:41 pm

You might wish to review this thread on the forum: Electrical Confusion

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Reply #4 – March 10, 2012, 03:33:56 pm

Start by turning off your Inverter.

Then verify that the shore power outlet is hot (voltmeter if you have one and are safe working with 120 VAC.

Does anything that runs on 120 VAC work in the coach-- roof A/C? microwave, etc?

If not, you might start the generator to determine if everything works.  If so, then you can eliminate checking  your 120 breaker box on to appliances, as they use the same wires/circuits on generator as on shore power.

Let us know what you fine and we can direct you.

Brett

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Reply #5 – March 10, 2012, 04:01:18 pm

Susan here:  I am coming off of my house, from an outside plug in. I think it is 20 amp, from the house breaker box.  I turned off the inverter. I started up the generator, and the one plug in that is under the kitchen cabinet closest to the refrigerator, which I think is different than the other plug-ins works. But none of the other plug-ins work. And the microwave does not come on like it usually does when I start up the generator.

I tried pushing the reset button on the GFCI in bathroom but nothing seems to click or anything. It is white, not red.

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Re: shore power problem

Reply #6 – March 10, 2012, 05:03:17 pm

Susan,
It sounds like you may have to replace the GFCI in the bath.  If you still have a problem after that, then it's likely the transfer switch located under the bed behind the circuit breaker/fuse boxes.

Peter

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Reply #7 – March 10, 2012, 05:05:29 pm

Just got off the phone from talking with Susan. Susan-- this should agree with the notes you took for your brother.

It is only GFI circuits that are tripping (bathroom GFI won't stay set, even with all appliances unplugged from the outlets).

All other 120 OK-- both A/C's work, etc. 12 VDC is fine at 13.2 VDC and not related to the problem.

Her brother is an electrician and is coming over to check house outlet for ground (old house) and then to disconnect the OUT wires from the GFI.  If the GFI does not reset with proven house outlet (short straight HOT, long straight NEUTRAL and round GROUND) and nothing on the downstream side of the GFI, she is off the get a new GFI.

If the GFI does reset with the downstream wires disconnected, she will start by drying out refrigerator and any outside or basement outlets and trace down what is tripping the GFI.

As I said on the phone, you are welcome to have him call if questions.

Brett

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Re: shore power problem

Reply #8 – March 13, 2012, 07:47:54 am

Has there been a resolution of this issue yet? Curious minds would like to know the result.

Brett provided an excellent exposition of the state of the issue on March 10, but I've not seen an update since then.

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Re: shore power problem

Reply #9 – March 13, 2012, 11:08:52 am

J.D.

Her brother is an electrician and will be coming over sometime this week to work on it.

Brett

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