GFI, Microwave and Outlets

[lightninghill]

I have a 2022 Montana 3831MS. This morning I had the microwave, coffee maker and a pedestal heater running at the same time. The circuit blew. I checked all the breakers in the control panel - reset all - nothing was tripped. I checked the fuses in the panel, one does not indicate when the fuse it pulled. All others show a red indicator light when the fuse is pulled. This fuse in particular is still good. The GFI plug will not reset. Other outlets in the kitchen, living area do not operate. Since Montana doesn't provide an electrical diagram, my assumption is the microwave, GFI and several other outlets are on the same circuit. Has anyone else experienced this? My next steps will be to open the control panel beyond the CBs and see if there are more fuses, and then pull the GFI apart and see if its junk.

[BB_TX]

None of those devices operate from 12 vdc, so not affected by fuses.
Unplug all those devices and then see if you can reset the GFCI. If you still can’t reset it you may need to use a voltmeter to see if you have 120 vac to the GFCI outlet.

[Cat320]

If you have an inverter, check it's circuit breaker.

[Carl n Susan]

What do you mean by the circuit blew? The microwave is usually on its own, non-GFCI, breaker. The other devices sound like kitchen appliances that would be plugged into the kitchen GFCI circuit. So there should be two circuits interrupted which implies a overload of the shore power.

If the a GFCI will NOT reset it means it has no power. You need to find the the upstream one and ensure it is operable.

The fuses in the fuse panel have no bearing on the AC circuits. Fuses protect 12V DC, circuit breakers protect 120V AC.

You reset all the CBs so they should be good (and not partially tripped just to fool you). Is the 120V on both side of the breaker feeding the kitchen and/or the microwave?

[BB_TX]

As a side note, the red blown fuse indicator will not illuminate unless there is some device currently connected to that fuse. The LED requires a path to ground to light up, and that path is thru the connected device. When the fuse is good there is no voltage difference across the LED and it does not light up. When the fuse is blown there is a voltage difference across the LED (and hence current flow thru it) and it does light up.

[lightninghill]

Originally Posted by Carl n Susan

What do you mean by the circuit blew? The microwave is usually on its own, non-GFCI, breaker. The other devices sound like kitchen appliances that would be plugged into the kitchen GFCI circuit. So there should be two circuits interrupted which implies a overload of the shore power.

If the a GFCI will NOT reset it means it has no power. You need to find the the upstream one and ensure it is operable.

The fuses in the fuse panel have no bearing on the AC circuits. Fuses protect 12V DC, circuit breakers protect 120V AC.

You reset all the CBs so they should be good (and not partially tripped just to fool you). Is the 120V on both side of the breaker feeding the kitchen and/or the microwave?

Thank you. Any idea where the upstream GFI would be? I do not have another in the bathroom or other area inside the trailer.

[twindman]

There may be a GFI in the outside outlet. Not sure what else it controls.

[BB_TX]

Regarding the outlet(s) that do not work. Does it (they) have test and reset push buttons on it? Or is it a standard looking outlet with a “GFCI Protected” label on it? If the latter it means that outlet is a standard outlet wired from a true GFCI outlet (one with push buttons) located somewhere else.

Another possibility is the wire connections in the back of the outlet. Unless they have changed, the outlets have press connections that cut into the wire when you press the outlet into a back plate. A cheap, fast, and easy wiring method. And did I say cheap? Works, but not a highly reliable wire connection method.

[Foldbak]

Like Carl said the microwave is on it's own circuit. I don't think it's a GFI problem. Did you check the pedestal power? Hot on both legs?

[firestation12]

Originally Posted by Foldbak

Like Carl said the microwave is on it's own circuit. I don't think it's a GFI problem. Did you check the pedestal power? Hot on both legs?

This is my first instinct, check the power at the pedestal. you can also check both sides of the 50 amp 2 pole breaker in your rv's breaker panel. There should be 240 volts.

[chessera2527]

GFCI will go bad i have replaced a few over the years one on the outside of my monty, if you know how to check the circuit behind the GFCI then you can tell what you have and do not have , if not get an electrician that does know

[wed]

Like said unplug and start with everything working your way through them

[krobb]

Check basement GFCI also. It may be the culprit!

[TheEaglesNest]

Agree with krobb. We had the same issue and discovered we had a second GFCI located in the basement.

[Daryles]

A GFIC will not reset IF...
it is bad. OR... You have no power to it.
You may be missing one of your two 50A legs from the pedistal.
I would start there and work your way forward.