Electrical- Power Surge

[Martin the Cat]

2018 Montana 3731FL. Had an issue where we head a pop and then smelt a hot electrical smell. It sounded like it was the Convection/Microwave oven...pulled the power cord and using a meter the outlet registered 197 volts (not good). Also pulled the fireplace surround and therebwas smoke coming from the fireplace unit. Using a meter the outlet registered 193 volts. We left both of those unplugged. During this time none of the breakers tripped. Our external progressive surge protector didn't show any issues either. Nothing happened for the next 12 days...everything worked great. Sitting at the table and heard two loud bangs and again smelled a hot electrical smell. This time we turned all 120 volt breakers of except what we had to use.

Any have any ideas what could cause this surge only on some outlets and not others? Thoughts how I can find were the issue might be?

Also, where can I get a wiring diagram (if one actually exists)?

[jimcol]

Something similar happened to a fellow MOC'er during a Branson Rally back in 2006. He was sitting in the unit when it happened. He remembered the ceiling run going to a very high speed before all the electronics fried. It ended up being an open neutral. I'd start at your electrical panel in the 5'er and check all connections for tightness. Work your way back to the pedestal including the lugs on your 50amp receptacle and your power cord.
After seeing what he experienced I try to make this part of my annual maintenance.
Going back to the 06 incident he was really lucky. 5'er was still under warranty and the dealer/manufacturer covered everything within a couple of days. Don't hear of warranty work like that anymore.

[BB_TX]

I would also guess an open neutral. An open neutral would cause a high voltage on one hot leg and a low voltage on the other hot leg in almost all cases. That is due to the difference of resistance loading on each leg.

Get an outlet tester so you can monitor it. The open neutral could be from the shore power source, or your power cord, or some wiring issue in the trailer itself. With power off, check all wiring connections in your power distribution center; hot, neutral, ground, +12 vdc. Loose wire connections have been a common problem. Sounds like yours might be some intermittent problem due to a marginal connection.

Wiring diagrams apparently do not exist as no one has ever been able to get one. They probably wire from general guidelines rather than diagrams, meaning no two are likely wired alike.

https://www.homedepot.com/p/Power-Ge...E&gclsrc=aw.ds

[jsb5717]

I recently had an open ground in our rig that turned out to be the plug from shore power. EMS caught it and denied power to the coach. So no harm, no foul. Since the error code indicated open ground it was easy to find the corroded ground pin in the plug and replace it.

Lesson learned: EMS should be standard equipment

Now, I'm not sure how to protect against and internal wiring issue once safe power is past the EMS system. But at least with EMS you can be assured that the power inside the coach is within range to begin with.

[rohrmann]

If you had a real EMS, not just a surge arrestor, and the problem was on the utility side of the EMS, you would be protected. This problem is likely at the pedestal you are plugged into, or even upstream from the pedestal. Do not leave the rig plugged into the pedestal until the loose neutral connection is located or you risk burning down your rig.

[Foldbak]

This is what I'm using. Is it enough?
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[jsb5717]

Originally Posted by Foldbak

This is what I'm using. Is it enough?
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Sorry no. That's only a surge protector. You really need an EMS system. You can search for EMS on Amazon to see some options. There are plug in types, similar to your surge protector. And there are hard wired solutions.

Here's the one I installed:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Foldbak]

So I wasted my money on the other? I should have bought this?
https://www.amazon.com/dp/B01N9MOY7B...4825f3bd9&th=1

[mlh]

What you have isn’t what you need.
What you need is exactly what you looked at on Amazon.
You are going to be like I am with a surge protector you have no use for.
Lynwood

[jsb5717]

Originally Posted by Foldbak

So I wasted my money on the other? I should have bought this?
https://www.amazon.com/dp/B01N9MOY7B...4825f3bd9&th=1

Sadly, that's the reality of it. I also had a nice, new surge protector to start out. I gave it to a travel buddy since he was using nothing. But I encouraged him to get the EMS as well.

[Lee-CI]

Originally Posted by jsb5717

Sadly, that's the reality of it. I also had a nice, new surge protector to start out. I gave it to a travel buddy since he was using nothing. But I encouraged him to get the EMS as well.

Sad indeed that sales personnel don't take the time or put in the effort to explain the true differences between a surge protector and EMS. It is really a matter of "pay me now" or possibly "pay me boat loads more later".
I think a lot of folks are now running the Hughes Watchdog. I hardwired the SurgeGuard unit in my signature line with a remote display and wouldn't pull out of the driveway without one. If fact if memory serves correctly that is exactly what happened - I wired up the unit before we ever left on our first shake down trip

[jsb5717]

Originally Posted by Lee-CI

Sad indeed that sales personnel don't take the time or put in the effort to explain the true differences between a surge protector and EMS. It is really a matter of "pay me now" or possibly "pay me boat loads more later".

I can't blame sales personnel for my purchase. Without knowing better I bought the surge protector because it seemed wise to have one. It was a little later, thanks to this forum, that I learned about EMS. I guess better late than never. As I stated in an earlier post in this thread, the EMS recently caught an open ground in my cable. Easy fix but I'm glad it caught it.

[BB_TX]

The one you have will tell if there is a problem with shore power such as open neutral. It just will not block power if you do.

[182flyer]

Foldbak; we also use the EMS-PT50X on our 295RL

[twindman]

The other thing EMS does that surge protector won't do is watch voltage levels. I blew out an A/C and something else way back in 2007 or so. Stopped in NEbrasks along I80 when it was like 100 degrees or more. Hooked up and the voltage was low (I guess) and fried a couple of things. Had to limp home with no A/C and stay in motels 2 nights (with our dog).
So after getting EMS, I have been at 2 places where it shut down the power because the voltage in the park dropped below 105 or so. One place was kind of low (maybe 107) and when I turned on the A/C it would drop too low. I guess I was running 2 A/Cs so I just turned one off until it cooled off outside.

[Foldbak]

Looks like I need to upgrade. Thanks for all your input.

[Rondo]

I went with the Hughes Watchdog and will not go back to anything else. Great unit and I get readings from it on my phone also if there is a problem.

[mlh]

Is the Hughes Watchdog just surge protection or is it an EMS?
Lynwood

[Rondo]

Lynwood it is an EMS and I won't go back to a regular surge protector. I can monitor the power 24/7 off my phone if I want and check anytime what is happening with the power coming into the unit.

[Mikendebbie]

I have a Hughes Watchdog also. It is plugged into my 50 amp here at the house. Couple of months ago it alerted me to some weird voltage spikes. The bulldog’s face lit up bright red! It protected the RV. I took a screen shot of the voltage from the app on my phone. I called the power company to come check my service and transformer. They had no explanation for the spike.