Need electrical advice

[dshinnick]

We have a 2005 Holiday Rambler Ambassador 40' DP with an outside Progressive Industries surge protector.

When we came back from running around we found the power off. The surge protector displayed an "E7", indicating a "High Frequency" error, whatever that is.

I cycled the 50amp switches on the power pole and the surge protector showed good power, no errors.

I have power on Line 1, but none on Line 2. I pushed the reset button on my inverter, it seemed to come alive but not sure what really happened there.

I reset all circuit breakers and checked all fuses. Nothing obviously wrong there.

I pushed the reset button on the GFCI outlet in the bathroom. It blinks green for half a second, then shuts off.

With my voltmeter I found that there is power coming to the GFCI outlet, but it's kinda weird:

upper right terminal to lower left: 48 volts
upper right to upper left: 120v
upper right to lower right: 48v

Maybe this is normal; I'm not sure.

Sure that it was a defective GFCI, I drove 15 miles to Home Depot, bought the identical model as I currently have, installed it, and have exactly the same situation.

I used my voltmeter to check the power pedestal, all seemed ok, so I removed the surge protector. No change in the situation.

The last weird thing: the GFCI DOES work on generator power! I was completely surprised. It comes on and stays on, and Line 2 comes up just like it's supposed to.

Ok, electric experts. Whaddya think?

Thanks in advance-

dave

[wolfe10]

Have you unplugged the refrigerator's 120 VAC cord-- try that (outside access door). If the GFI is tripping because of a problem in the refrigerator, this should identify/eliminate the issue.

If that doesn't cause it to be resettable and stay reset, unplug everything that is plugged into either the GFI or any outlet downstream of it. See if it will stay reset. If not, you have either a wiring problem or if a GFI trips enough, it may not reset.

And, yes, refrigerator 120 VAC heating elements are one of the most common causes of GFI failure.

[dshinnick]

Ah, I spoke too soon. GFCI shutoff again. We put the fridge on LP, redid all the steps that made it work last time, and no-go. The GFCI shuts off almost immediately.

Unless someone else has some thoughts, I guess we'll just be on generator for the rest of the evening.

[dshinnick]

Well, enblethen, the next time I see you, the beer's on me.

I shut off all the breakers, then powered on the main and the inverter (which is the circuit the GFCI is on), and reset the GFCI, and, surprisingly, it stayed on. My wife watched the power meter with bated breath while I powered on the rest of them, and we're back up and running.

Oh, how I love this forum! Thanks for the help guys.

[DrewE]

High frequency means that the incoming power's frequency was much too high (greater than 69 Hz, if I remember the specs—rather an unusual fault to have, as utility power frequency tolerance is very tight, within a tenth of a Hz (and more accurate long-term) and cannot vary across the AC power grid due to the physics of AC power distribution. Maybe extreme noise on the line would cause the error, or an intermittent connection or something along those lines.

The voltage measurements for the GFCI are not surprising give that it was tripped. Your two 48 V measurements are to an open (floating) circuit. An analog voltmeter (with a lower input impedance) would likely read zero volts, and arguably give a more informative reading in this case.

It sounds like you have a couple of problems (which are possibly related): a ground fault, causing the GFCI to trip, and some fault preventing the second leg from giving power. Since the generator works, it would seem to possibly be in the input cord or the EMS or its wiring.

[dshinnick]

Remember that I did check and reset the breakers. I'll do it again as you described.

And, the fridge is on L1 which has not lost power. I was surprised to see it on AC when I first began to investigate. I didn't know it was on L1. I assume, then, that it could not have a bearing on the problem.

[You_can_t_take_]

I had the same issue with my GFCI. Traced it to the refrigerator (which was downstream from the GFCI) by pulling the plug at the back of the fridge and finding that the GFCI would not trip when I did that. Turns out my 120V fridge 'element' needed to be replaced. Apparently this is a fairly frequent problem when the 'element' is starting to go as the GFCI will detect any small fault.
(See my recent post about my GFCI)

[enblethen]

Tripped breaker in the 120 volt distribution panel.
Turn off all breakers applying light pressure toward off. Turn on main breaker. Turn on branch breakers one at a time. Reset GFCI receptacle.
Next check the inverter circuit breaker. Some have a small red or white button to reset.