Electrical nightmare!

[Tiller]

Lengthy post!


Ok, so I am new to the RV game. We are about to move into our Montana 3855br and it is currently plugged into the service in my shop. It worked great for about 2 weeks, then I went out to check on things and battery was dead and no power inside. OK, so I charged batteries and all 12v systems were working properly. Great! However, none of the 120v would work. All breakers were still in the "on" position and nothing obviously burnt up. So I went to the surge protector as we have recently had storms pass through. The surge protector reads " L1 and ground reversed " .....

I have an electrician come out just to see if we could isolate the issue and now we are both confused... lol.

We attempted turning off different breakers and seeing if it would change the readout on the surge protector. It did. Come to find out, when the kitchen, bedroom, kitchen GFI, converter, and microwave are in the off position and all others in the on position, the surge protector reads that things are normal....


NOW to the confusing part. We turned the "problem" breakers on individually to see what that would do. Some cause a "L1 and ground reversed", some cause a " L2 and ground reversed " and then one of the caused a "reversed polarity ".
Also, to add to the confusion, I can get the microwave to turn on, but AS SOON AS I hit "start" it turns off then back on. The TV has power and has no issues operating, until I try to use the microwave, then it restarts just as the microwave. Also, the 120v plugs read "reverse polarity" with a fault detector.....


I am at wits end with this thing and I haven't even gotten to use it yet.... can someone please point me in the right direction to fixing it? Or has someone had similar issues?

Thanks for any feedback!

[chuckster57]

Welcome to the forum

Some more information would help:

Your trailer is 50A service right?

Any adaptors (dog bones) being used?

Brand and model of EMS?

[Tiller]

Thanks, friend!

Yes, its is 50A.

I do not use any adapters and I have power to the end of my shore line.

The EMT is a Surge Guard 44390

[chuckster57]

Good. Now, is the outlet wired for RV?

[Tiller]

Now that is a question I do not know, therefore I am going to venture to say that no, its is not. I did not install it, so I don't know. I can pull the face off it and see. What am I looking for exactly?

[chuckster57]

You need to make sure the outlet is the correct NEMA ( I don’t know) and that it is wired correctly. Your electrician should be able to verify the wiring.

You should also verify that the circuits giving you wierd readings are wired correctly.

[Tiller]

So, upon some googling , I found that it is wired as a 30 AMP / 120v.

**** The wall plug is wired in this configuration.

[Tiller]

I should have noted, that this camper was lived in by some of our friends for 2 years before we took ownership. They never had any issues related to this.

[chuckster57]

I thought Montana’s were all 50A. Your shore cord has 3 or 4 blades?

[Tiller]

I apologize, I just went and looked, I do use an adapter ( I don't know how I I didn't notice) So it goes like this, 30 amp/120v from the wall, to a 30 amp/50 amp adapter, to the EMS, to the trailer (which is 50 amp).

[chuckster57]

Ok. At this point I would question the adapter. What brand?

[jasin1]

I would look at your 50 amp receptacle…is it definitely a dedicated circuit? Is there anything else at all coming off that circuit that has been connected or plugged in recently? I’d get someone with electrical knowledge to pull the cover off the receptacle and check all the connections
I’d also check the gfci itself…that could be defective…

You said everything worked great for two weeks then something changed.. have you done any upgrades to the rv?….I’d suspect it’s in your supply voltage or gfci itself but I could be wrong…that’s where I would start though

[jasin1]

Also is your ems 30 or 50 amp?

[Tiller]

Originally Posted by sourdough

What changed from when they were using it to what you did to use it? I assume you changed locations and how/where it is plugged in and into ??? Do you know how to use a VOM? If it worked fine for them for 2 years and it manifested itself when you took ownership and tried to use it....look for what changed.

It did change location (about 20 miles )
And It changed the plug in design by being used in a dedicated service inside my shop rather than a campground. It also worked for 2 weeks like this and nothing changed until this.

[Tiller]

Originally Posted by jasin1

Also is your ems 30 or 50 amp?

The receptacle is 30 amp
The ems is 50amp

Also, this is a dedicated service, yes.

There was nothing done to the rv or power supply during those 2 weeks that it worked great.

[Tiller]

It's is a couplago

[jasin1]

What all did you try and run off the 30 amp receptacle? is it breakered at 30 amp in the panel? …chucks idea about the adapter is probably a good place to start but I’d just wire a dedicated 50 amp service for the rv.

Also is your shop a separate building from your house with its own electric service. Or is it a subpanel from your main house?

Neutrals and grounds with sub panels can get dicey and have to be wired appropriately

[chuckster57]

Originally Posted by Tiller

It's is a couplago

Never heard of that brand.

[jasin1]

Lastly maybe you have an issue with a neutral wire at your service head as you stated that storms recently passed through…anyway good luck..don’t rule out the service entrance cable at your service head as you can still see a hot wire but no neutral

[jasin1]

Originally Posted by chuckster57

Never heard of that brand.

Sounds like the brand where you need to purchase a “couple of them” because they fail?