2021 Montana 383th Electrical Issues - Montana Owners Club

shippilot · 05-09-2022, 07:25 PM

I have a similar electrical problem. All my GFI protected receptacles are out. GFI is in the bathroom. power is coming in at 124 volts on one leg. but the other leg shows about 290 volts. these voltages are with the GFI disconnected checking just the wires. There is another odd occurrence. on the receptacles that are GFI protected and with the GFI totally removed in the bathroom, i get the following readings. all breakers turned off. basically 0 volts. turn on the Microwave and I get about 35 volts from the GFI rec. leave the Mic. on and turn on the fireplace and the volts go up to about 70 volts in the GFI rec. You can see what is happening. As I turn on breakers the voltage continues to climb in a receptacle that is protected by a GFI that "by the way" is totally removed. The coach is still under warranty, but I bought the rig from Texas, and I live in Washington. the local dealers won't service it because they didn't sell it. It appears I'm on my own to figure this out. Any ideas?

Edited to create a new thread for this issue.Site Team

BB_TX · 05-09-2022, 07:53 PM

shippilot - you obviously have a power problem. But just as obvious a different problem from the post you replied to. I suggest you request a moderator to move your post to a new thread so that answers and suggestions don’t get intertwined.

But one question in the meantime. You say you measure 124 on one leg and 290 on the other. Where exactly are you measuring those voltages?

shippilot · 05-09-2022, 07:57 PM

sorry about jumping the other post, don't know the protocol. How do I start a different post?

shippilot · 05-09-2022, 08:03 PM

To answer your question. I disconnected and removed the GFI. Now looking at the bitter ends of the two wires leads coming into the plug box from the wall in the bathroom. Put the voltmeter on the bare wires to read the voltage readout.

shippilot · 05-09-2022, 08:25 PM

I hope this is a new post. turns out I stepped on someone else's electrical problem post. I have an electrical problem. All my GFI protected receptacles went out. GFI is in the bathroom. I removed the GFI and checked the bare wire ends. One of the wires was coming in at 124 volts, but the other leg shows about 290 volts. these voltages are with the GFI disconnected checking just the wires. There is another odd occurrence. on the receptacles that are GFI protected and with the GFI totally removed in the bathroom, I get the following readings. all breakers turned off. basically 0 volts in the GFI protected receptacles. Turn on the Microwave and I get about 35 volts from the GFI receptacles. leave the Mic. on and turn on the fireplace and the volts go up to about 70 volts in the GFI rec. You can see what is happening. As I turn on breakers the voltage continues to climb in a receptacle that is protected by a GFI that "by the way" is totally removed. The coach is still under warranty, but I bought the rig from Texas, and I live in Washington. the local dealers won't service it because they didn't sell it. It appears I'm on my own to figure this out. Any ideas? Thanks

Edited to consolidate this Post with its duplicate - Site Team

BB_TX · 05-09-2022, 08:29 PM

There are many sub forums here to discuss different issues. Clicking on a forum you will see a clicky labeled Start New Thread. If Carl (Carl n Susan) sees this he will probably move this to a new thread for you.

You have two wires one measuring 124 and one measuring 290. Since shore power 50 amp service should have no more than 240 vac I can’t see where 290 could come from. What are you connecting your other meter lead to as a reference point?

shippilot · 05-09-2022, 08:43 PM

I agree, I checked the main power coming in from my houses 50-amp shore power at the breaker box in the coach and it reads 250 volts. I'm also perplexed at how I'm getting 290 volts. I'm not an electrician but know the basics and this just doesn't make sense.

By the way, I think I may have made another forum protocol fubar. I started a new feed about my electrical problem with the same basic contents. Its title is "2021 High Country 383TH"

Ahdmeyer · 05-09-2022, 09:10 PM

sounds to me like neutral problem only way you can get that high a voltage on one leg of a 240 volt feed is an open neutral or a problem with the utility transformer. i could be at the pedestal or in your rig if it is the neutral. without load you should get the correct voltage. as you apply more load with the neutral bad it will go up on one leg and down on the other.? need to check it first at the feed and go from there. if comfortable working with electric check all the lugs to make sure they are clean and tight.

**Carl n Susan** · 05-09-2022, 09:15 PM

The multiple Threads/Posts have been merged together to enable one consistent place to discuss and resolve. It might be a lttle disjointed to read, but all the comments are in one place.

shippilot · 05-09-2022, 09:26 PM

thanks, I'm pretty sure it's the rig. I checked the house pedestal. again, I'm not an electrician but 50-amp service. two leads coming from house into pedestal. 125 volts each. also checked the breaker box inside the rig, 250 volts.

I will check all the neutral leads inside the rig tomorrow. thanks

shippilot · 05-09-2022, 09:28 PM

Sorry for the confusion, thank you for getting me straightened out.

Ahdmeyer · 05-09-2022, 09:30 PM

just another point it could be in the cord also. good luck let us know either way

Daryles · 05-10-2022, 05:40 AM

You need to measure
Hot to ground voltage =
Neutral to ground voltage =
Hot to neutral voltage =

You need to do this at the pedistal
At the end of the power cord going into your rig.
At each of the 50A breakers (left = , right = )
At each breaker (turn off all beakers)

I suspect you are missing a ground or neutral.

jsb5717 · 05-10-2022, 08:11 AM

I'm no electrician either, but it does sound like there is a wiring problem coming from the house or through the cord. You shouldn't be getting 250v inside the trailer. Everything should read at 125v or 12v (post-converter readings). I would be tempted to try using a dogbone adapter that connects only 110v to the trailer to see if that corrects the issue. It's possible, though, that the electrics are ruined in the trailer if it's getting too much voltage from the house.

BB_TX · 05-10-2022, 08:13 AM

Quote:

Originally Posted by shippilot

Sorry for the confusion, thank you for getting me straightened out.

We are all a very friendly bunch here. Much more so than some other RV forums.

I agree with Daryles. Check voltages all along the way from the source to the inside. And check all screws on your 120 vac load center and on your 12 vdc fuse panel. All hots, neutrals, grounds, and 12 volts. I found many screws barely tightened on mine when new. Poor connections can cause weird things to happen.

Were these outlets working correctly at one time?

jsb5717 · 05-10-2022, 08:17 AM

Also, re-reading the original post, if the OP is testing the GFI outlet correctly, then there shouldn't be any voltage out of the ground side of the plug. 125v at the smaller slot, 0 voltage at the larger, neutral slot. Am I thinking correctly?

BB_TX · 05-10-2022, 08:19 AM

Quote:

Originally Posted by jsb5717

I'm no electrician either, but it does sound like there is a wiring problem coming from the house or through the cord. You shouldn't be getting 250v inside the trailer..........

Actually you do get 240 vac inside the trailer from a 50 amp service. Nothing in our Montanas use 240 vac. They just use the two 120 vac hot legs independently to get more power. But some RVs, especially high end MHs, may have some 240 vac appliances. And there has a case or two of a MOC member installing a 240 vac clothes dryer.

rames14 · 05-10-2022, 08:20 AM

Shippilot, contact Keystone if you are uncomfortable doing it yourself. They may authorize a mobile tech to come to your unit. Has it ever worked? If it worked and now it doesn’t, it is probably just a wire loose. If you want to tackle it yourself, starting at the pedestal and check per the diagram above from Daryles at each step. Since there are so many differences between the High Country and Montana’s, I am not sure if you have a transfer switch, inverter, etc. but next check where your cord terminates at the panel. Keep us posted on your journey.

BobStack · 05-10-2022, 09:13 AM

Sounds like the one of the incoming legs is in contact with the ground some how. That would trip the ground fault and cause the voltage readings you described.

jsb5717 · 05-10-2022, 09:13 AM

Quote:

Originally Posted by BB_TX

Actually you do get 240 vac inside the trailer from a 50 amp service. Nothing in our Montanas use 240 vac. They just use the two 120 vac hot legs independently to get more power. But some RVs, especially high end MHs, may have some 240 vac appliances. And there has a case or two of a MOC member installing a 240 vac clothes dryer.

Thanks, this can get confusing for us backyard electricians. My understanding has been that 50amp RV outlet wiring is critical so as not to destroy internal wiring and circuits.

The diagram below is how I've understood it...that 2 separate 125v/50A legs come into the RV power center and are kept separate (yes, 250v total). If you lose one of the 2 legs of power then you lose half of of your outlets...depending on which items are connected to which leg. In order to install a 240v washer/dryer, you'd need to run wiring from each side of the power center, wouldn't you?

I'm wondering how the OP would be reading 240+ volts anywhere in the trailer since everything is distributed as 110v.

You may also like: