Campground GFI tripping

[jhudson]

Hi all,

I got a problem at the campsite, plugged in a 20 amp GFI outlet(only thing available where I am), and when the furnace kicks in the GFI trips. Not the circuit breaker which is a 20 amp, but the GFI outlet that has the test/reset button. This just happens with the furnace and nothing else. Anybody have any ideas? I am thinking the campground outlet, but why then only when the furnace turns on. I have not had any problems plugged in to the generators but that was on a 30 amp circuit and my home which is again a 30 amp circuit. Maybe something came loose with the trip down?

Jay

[BB_TX]

The 30 amp circuits are not likely GFCI circuits.
A GFCI outlet works by comparing the current flowing into the hot side to the current flowing out the neutral side. They must be almost exact of each other (within something like 4 milliamps) or it will trip. More difference than that indicates current is leaking out somewhere it should not.
I guess I was thinking the furnace was all 12 VDC, not 120 AC. But a fault on the DC side should not trip the GFCI. But obviously it is affecting the AC power somewhere.
Apparently you have a ground fault in the furnace or furnace wiring that somehow affects the AC wiring. Since it does not trip the breaker it is not likely a fault on the hot side. Most likely a fault on the neutral side. Maybe a scraped wire touching metal. Maybe some water in an electrical box associated with the furnace.
Maybe someone more knowledgeable of the furnace power arrangements will chime in.
Of course it could also very well be a bad park outlet. You might first try asking the park maintenance to replace the outlet and see if it still happens.

[WaltBennett]

x2 what Bill wrote, although I'd think the GFCI outlet is OK if nothing else trips it. There really isn't all that much to a furnace - just a blower & associated safety stuff that keeps it on when there's heat in the exchanger. Possibly there's something going on with the thermostat that would cause this (but that's also DC)? You've got a weird one for certain and may have to take the furnace & its wiring apart.

[Phil P]

Hi

Does the furnace keep running after the GFCI trips?

Phil P

[jhudson]

quote:Originally posted by Phil P

Hi

Does the furnace keep running after the GFCI trips?

Phil P

Yes because it is on 12volts

[Irlpguy]

Unless they have done something new with the furnaces, then it should run off the battery alone as it is all 12V and the only time AC would be brought into the equation would be if the batteries are low and the converter is being required to supply all the 12V for the lights, fridge and furnace. It may not be a problem with the GFCI but simply overloading the 20 amp circuit.

If the furnace cuts out when the GFCI breaker does, then I would say there is a problem with insufficient 12V from the batteries.

Do you get an error message at the fridge when the breaker trips, since it requires 12V as well to operate. Can you operate the microwave with no problems.

I am assuming the GFCI breaker is at the pedestal.

Since there is no "direct" connection between the furnace and AC, I would be looking at the converter and battery condition.

[Irlpguy]

When the furnace fan comes on there is considerable current draw, tripping the breaker at that point might point to a loose terminal on the charge side of the converter as it steps up to replace the DC being drawn from the battery.

Just guessing since you indicate the furnace does run on battery alone.

[K0LCB]

I had a converter that leaked to ground from the case. I mounted it on a piece of heavy rubber belting and solved my problem

[jhudson]

quote:Originally posted by Irlpguy




Since there is no "direct" connection between the furnace and AC, I would be looking at the converter and battery condition.

I thought I would get back on what I found. Friday was interesting but I did get it figured out.

1. Irlpguy was right on about the converter and battery condition. The direct link to the outside post is the converter. Problem 1, bad battery (even though it was new)load tested, would not hold voltage causing converter to ramp up to meet demand of furnace. I replaced battery, checked charging circuit of converter, all checked out fine now.

2. Everything ran fine until the evening moisture started sticking to the ground and cords. GFI on post started to trip again!!!It now didn't matter if it was 12 volt or 110. I hate to work on things in the dark!! Anyway I shut the main breaker on the post which has the 20 amp GFCI and took a close look at the outlet. Well to my surprise, a bad connection on the neutral and bad ground wire. I guess this lead to some current flow/loss when then got damp. I took care of the connections and all was well for the rest of weekend.

Typically I would not work on a campgrounds electrical post and just call them. This campground being a state park in MA and being poorly staffed at this time of year would mostly likely mean that I would not have power in the evening and would have to run the generator. I look at it this way. The next guy will be all set.

Thanks for all the input as this one didn't make sense to me at why the furnace would "trip" the GFCI being it ran on 12v until IRlpguy sent me to the battery/charging part of the converter.

Jay

[K0LCB]

Glad you got her figured out! Have some fun