Problem with GFI circuit

Topic: Problem with GFI circuit (Read 936 times) previous topic - next topic

Problem with GFI circuit

February 07, 2013, 05:06:08 pm

I've got a weird one. The DW turned on the vacum today and electricity to all the receptacles went out.

I checked the breaker on the circuit panel and it's not tripped. Check the GFI in the bathroom and the green light is out. Punch the reset button and nothing happens. Check the Powerwatch by the door and it shows 126 volts coming in. Figure it's the GFI and pull out my spare. Before I install it I check voltage on the line in. Hot to neutral is 3 volts! Check hot to ground and it's 120 volts. No sure where to go from here...

Anybody have any ideas?

see ya
ken

Re: Problem with GFI circuit

Reply #1 – February 07, 2013, 05:14:45 pm

Since the problem started when the vacuum was turned on, assuming you mean it's a central/built in unit, I'd start there.

Re: Problem with GFI circuit

Reply #2 – February 07, 2013, 05:47:47 pm

Don't know where you measured the line in and saw 3-volts.

If you can, measure hots to each other and to ground & neutral at outside pedestal, open main breaker box and do the same. If ok outside and not ok inside, it is probably the transfer switch, which can also be opened and measured

A loose neutral connection is very dangerous on 50-amp, as a good neutral is required to keep 120-volt & 240-volt working in harmony.

Re: Problem with GFI circuit

Reply #3 – February 07, 2013, 06:23:21 pm

Possible causes can be a faulty vacuum cleaner, faulty A/C wiring, a faulty GFCI recepticle, faulty shore power supply, or a faulty transfer switch.

Have you installed screws anywhere recently, or had other work done? I did trouble shooting of A/C wiring for a Foretravel owner a year ago and there were two problems: firstly, a screw (installed by owner) was grounding a recepticle box to the frame, and secondly, the hot and neutral wires were reversed on a kitchen recepticle which was done by some young guy trying to be helpful with the Owner's ground fault problem.

Unplug the vacuum cleaner and attempt to reset the GFCI. If it resets, problem is with vacuum cleaner.

GFCI recepticles, sometimes do become faulty, for no apparent reason, even if there was no ground fault.

Remove the load wires from the GFI recepticle. If it resets now, problem is with the A/C wiring.

Remove all wires from GFCI recepticle and With your voltmeter, check hot (black) to neutral (white). The supply wires from the panel will show 120v from hot to neutral while the load (to kitchen) will show zero. If supply shows 3 volts, problem is with the supply (campground power, breaker, selector switch or supply wiring).

Be very careful when installing the GFCI to attached the supply and load wires to the correct terminals.

If you want to check for ground wire faults, you must disconnect the ground wire in the panel for the circuit to be checked. All ground wires and metal recepticle boxes should be grounded in the main panel and no where else.

Re: Problem with GFI circuit

Reply #4 – February 07, 2013, 06:25:26 pm

@Michelle Not the built in vac a plugin Dirt Devil floor vac. In our coach almost all of the receptacles run through the GFI in the bathroom. Seems like it would have been better to split the load between both legs of the circuit panel. It's easy to overload the single 20amp circuit with a couple of 1200 watt plugin heaters.

@Barry Sorry I wasn't as clear as I could have been. Voltage at the pedestal is 240 between the hots and 120 hots to neutrals and hots to ground. So I pretty sure I'm OK there. At the circuit panel see the same voltages. At the wall GFI receptacle is where I see the 3 volts hot to neutral & 120 hot to ground. All other circuits in the coach are working correctly. Best guess is an open in the neutral??

I did check to see that all of the neutrals & grounds are tight at the circuit panel. Still 3 volts hot to neutral at the line side of the GFI receptacle. Hummm I could trace the hot lead from the circuit breaker to find the returning neutral. Disconnect the neutral from the circuit box connect a length of wire and run it to the bathroom and do a continuity test to the neutral there. I'll let you know what I find. Luckily it just quit raining. I can get to my wire in the bay now!

see ya
ken

Re: Problem with GFI circuit

Reply #5 – February 07, 2013, 06:36:49 pm

check the little push in breakers on your inverter. AC runs thru the inverter. I had mine pop when running electric heaters.

Re: Problem with GFI circuit

Reply #6 – February 07, 2013, 06:47:28 pm

Unplug everything down stream of the GFI, TVs and microway,washing machine ect.

Re: Problem with GFI circuit

Reply #7 – February 07, 2013, 06:59:44 pm

Ran the continuity test on the neutral. Shows open.

Did the same test on the ground wire to prove my process and it was good. Looks like I'll be crawling around in the bays tomorrow morning.

Hope it's not a rodent problem! Maybe it's just a wire nut in a junction box...

Thanks for the help brainstorming!

see ya
ken

Re: Problem with GFI circuit

Reply #8 – February 07, 2013, 09:08:46 pm

Ken,

Our coach has an electrical sub panel where both hot and neutral main feed come directly from inverter. This sub panel feeds our GFCI outlet and other loads. Are the other inverter panel loads working ok? Open sub-panel and meter the wires.

The input power to the inverter comes from main breaker panel and is passed thru the inverter via a double-pole relay inside the inverter. There may be a round-button circuit breaker on the outside of the inverter.

Re: Problem with GFI circuit

Reply #9 – February 08, 2013, 11:18:33 am

My inverter is the old Taytronic 1500 watt. It's mounted under the entry stairs so had to remove everything from P2 to get to it. The circuit breaker is built into the on/off switch. It wasn't tripped. Power cycled it anyway just to be sure. Still the 3 volts at the GFI line side. <sarcasm>Had a stroke of brilliance</sarcasm> and turned on the inverter. Now I have 109 volts at the GFI line side. My electrical skills are rudimentary at best but that seems low to me.

I don't use the inverter very often. We spend most of our time in campgrounds with full hookups. I do remember heating some water in the microwave during a trip using the inverter and it took 10 minutes to boil the same amount of water that campground power takes a little over 3 minutes. Probably the lower voltage?

So what to do now. Any other test I can do to confirm it's the inverter? Am I due for a new inverter? The Taytronic has a remote panel that is used to turn it on and also a switch to direct the output to the microwave or to the receptacles. Do modern inverters have the same setup?

@Tom & @Barry thanks for pointing me to the inverter. Karma for you!

Edited to add: Barry I don't have a separate sub-panel for the inverter.

see ya
ken

Re: Problem with GFI circuit

Reply #10 – February 08, 2013, 11:20:45 am

Barry, not all Foretravels use the pass through relays in the inverter, my 1996 U320 did not. Instead there was a second auto selector A/C switching relay, I believe because the inverter relays were 30amps while the auto selector was 50amps.

Re: Problem with GFI circuit

Reply #11 – February 08, 2013, 11:25:13 am

@Wyatt Thanks for the info. I'll pull out my wiring diagrams to see if can tell how the inverter gets to the GFI. I'm out for most of the day today so will be later tonight before I can get to it.

see ya
ken

Re: Problem with GFI circuit

Reply #12 – February 08, 2013, 11:43:59 am

Taytronic Inverter? That changes everything. Power does not pass through inverter. It only has a 120VAC output. That output feeds to two relay boxes under the bed. Each of those acts just like a transfer switch for two circuits: "microwave" and "outlets" which corresponds to the selector switch on the inverter panel. With the inverter off the shore current for each of those circuits passes through the "normally closed" side of the relays (they switch both the hot and neutral with double pole relays). I suspect that the normally closed contacts might be acting up and giving you "no" to low voltage.
Just as something to try: turn your invert on and off several a dozen times (set switch to "outlets") to exercise the contacts - maybe they will start to conduct again.

BTW: It's normal to double the time to microwave things on the inverter (Taytronics only) due to it's inferior sine (square) wave output. Doesn't seem to hurt the microwave - I still have my original. I got rid of the Taytonics about 5 years ago.

The next thing it could be is the input wires (probably the nuetral) have a loose connection on the GFI outlet. This happend to me when I had a heavy load on that circuit (elecrtric heater, etc.) and I think the wires would get warm and expand/contract with load changes and work the screw loose that was holding the wire on.

Re: Problem with GFI circuit

Reply #13 – February 08, 2013, 12:12:25 pm

@John Thanks for the info! I'll try your suggestions. BTW what did you replace your Taytronics with?

see ya
ken

Re: Problem with GFI circuit

Reply #14 – February 08, 2013, 01:36:45 pm

I happened to find a used Xantrex RS3000 for a song and have a more complicated installation for how I use it. If you're someone who rarely uses the inverter it doesn't make much sense to do what I did. The best solution for you will depend on several other factors (is your charger already upgraded?, watts required?, how much money you want to spend, etc.) and can be done many different ways with associated opinions as well. Such a subject is worthy of another thread. If you really don't use the inverter much, I would suggest keeping the Taytronic until it dies. A failed unit will not cause power loss when on shore or generator power. In general, new inverters only get better and cheaper with time. I'm pretty certain your issue right now is wiring.

Re: Problem with GFI circuit

Reply #15 – February 08, 2013, 02:10:38 pm

When you took your voltage measurements at the GFI receptacle did you remove the wires from the receptacle? If not the GFI outlet may be bad and giving you a weird reading.

Roland

Re: Problem with GFI circuit

Reply #16 – February 09, 2013, 01:56:55 pm

Quote

Taytronic Inverter? That changes everything. Power does not pass through inverter. It only has a 120VAC output. That output feeds to two relay boxes under the bed. Each of those acts just like a transfer switch for two circuits: "microwave" and "outlets" which corresponds to the selector switch on the inverter panel. With the inverter off the shore current for each of those circuits passes through the "normally closed" side of the relays (they switch both the hot and neutral with double pole relays). I suspect that the normally closed contacts might be acting up and giving you "no" to low voltage.

@John you're the winner!

Checked under the bed and found the RP2L transfer switch. Tested the line side of the GFI circuit and found 120v. Checked the load side and found 2.7v. Ding, Ding, Ding! For a work around I connected the line side neutral to the load side neutral and the same for the hot wires. The disadvantage is that no inverter for the GFI circuit. The advantage is that I have power back to the GFI. I don't see that this will cause any other problems. If anyone disagrees please let me know.

As for the fix. Can I just pull the relay and clean the contacts or should I just hunt down a replacement? The other choice is to just leave it. At least I have some time to consider my choices now.

As always you guys are awesome. Saved me a lot of head scratching.

Oh everyone loves pics so here ya go... The iPhone camera doesn't do well in low light so some are pretty fuzzy.

see ya
ken

Re: Problem with GFI circuit

Reply #17 – February 09, 2013, 03:57:05 pm

Ken, the relays look to be Potter and Brumfield, pull one and check for the model# the Google Mouser electronics and check with them, cleaning contacts on a burnt relay is just a short term fix.

Re: Problem with GFI circuit

Reply #18 – February 09, 2013, 06:04:37 pm

I was just wondering .Do you have control power to termanal 86 and a good ground to terminal 85 of the relay? Gam

Re: Problem with GFI circuit

Reply #19 – February 09, 2013, 09:00:35 pm

You can also check with Graingers to see if they have a relay to replace your bad one. You would have to check for the coil voltage if ac or dc and if 120 or 12 volt

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