DonF, thanks. Let me ask if I can measure the amperage at the breaker or the GFI outlet with a multimeter. It seems that would tell me if the breaker or the GFI is weak. Thanks

First off, what are you asking about? Is this a continuation of another thread?
It is best to keep all replies in the same thread to avoid confusion.

A GFI is NOT an overcurrent device. A amp meter will tell you nothing as to the condition of a GFI.
You would need a professional GFI tester, such as an Ideal Sure-Test, to test the trip level of a GFI. These testers are not cheap either.

Using the average DMM for current testing will usually not work as most DMMs have a low current level, like 10A or so.
Also, it can be VERY dangerous using a DMM for amperage tests. You must place the leads in series with the load and have it live for the test.

Thanks, Stanfortyman - that's the info I needed, not necessarily what I wanted. Runner

Runner,

Stan makes a great point about Digital Multi Meters. They make clamp on ammeters to test amperage levels.

But lets go back and re-visit your problem.

What type of device are you plugging into the circuit?

Do you know what the "Inrush" amperage for the device is?

Does the tripping occur immediately when you plug your device into the receptacle or after you turn the device on?

Since a breaker and GFCI devices operate under different circumstances, why do you believe that the GFCI is opening and not the breaker?

Don, for a couple of years I have kept my motorhome in a storage garage plugged into the 15amp GFI outlet. This allows my refrig to run and keep the house batteries charged. However, I got tired of all the venting of the batteries - so, I had to replace the batteries and I got a "Battery Minder" smart charger to keep the batteries charged. Now in storage I use a battery dissconnect switch but when I plugged the MH into the GFI to run the refrig before going on a trip, as soon as contact was made, the GFI popped. I then took the MH to another 15amp outlet and It also popped on contact. Then I drove it to my home and tried it in my garage where I dissconnected all other running electronics (I think) and again it popped. I took the MH to a repair shop to have my converter/charger checked and they ran it on a dedicated 120v 15 or 20amp outlet without problem for about 30 minutes. I used the MH for a few days camping plugged into the full service 50amp at the campground without incident. I think the 15amp GFIs that I have may be weak, but do not know how to test them. Thanks, runner

I'll bet the charger pops a GFCI. I'll bet it uses a switchmode power supply with no mains filtering.

The GFCI is not supposed to be a current protective device, so it's not popping with overcurrent.

Refrigerators can also cause problems with GFCI's.

I'd like to know the specs of the charger or a link to the manual online. You could call the manufacturer and ask if they use a switchmode supply and if they use RFI line filters in their design. They might be identifiable with a picture of the insides. No guarantee. You can post pics using "Go advanced/Manage attachments"

If your concerned about really wanting a GFCI protected trailer at home, we might be able to find some alternatives to be able to raise the levels.

A filter such as the Isobar from www.tripplite.com would work for you, however if it's the charger, then filters should be incorporated there not necessarily in the form of the ISOBAR.