Electrical burn at ATS

[billhealy]

Sent to Ron Scarberry at Heartland Tech Support

Rig is a 2009 Big Horn 3400RE ID:203247


On Thursday, August 4, we camped overnight at Rocking A Campground (site 71) in Vernon TX. We connected through a TRC 50 AMP surge protector. I woke up about 1:30, No rear A/C. Checked and discovered that the washer, dryer, and all curb side outlets were dead. Front A/C, fridge, microwave, right side outlets were okay. Checked all breakers and all appeared okay. Following morning we spoke to a local mobile RV service who checked the power at site 71 and stated that the power was clean.


At Sam Club road service recommendation we took the rig to TexasRVGuys in Haslet, TX. They checked the electrical system completely and found that the ATS and connected wire were burned. It could be a fire hazard. They could not find the cause of the problem. They replaced the ATS and wiring. All now appears okay. I am enclosing 2 pics that they took.


We are concerned that there may be a serious hazard that could result in a fire and potential death. We are going to post this on the Heartland Forum.

If anyone else has had a similar problem, please let us know. b2healys@gmail.com

PS. We have been told that this is the first problem of this type.

Bill & Bev Healy
Cookeville, TN

 

[Jesstruckn/Jesstalkn]

It was more then likely a loose connection in your Automatic Transfer Switch jam screws. (Or what ever there technical name is) If that is where the wires were burnt that should be the location of the problem. It's a good Idea to go through and tighten all of your connections up once, (with RV UNPLUGGED from shore power) to prevent this kind of problem.
Resistance causes heat.
I am no professional by any means but that has been my experience and others on this forum.

 

[danemayer]

Our transfer switch got fried 2 years ago and damaged several inches of wire on each side of the box before failing. The reason it's in a metal box, as with most electrical connections, is to minimize fire hazard.

A loose wire will increase resistance, generating heat that causes serious damage to the switch. Another possible cause is pitting on the surface of the contactors inside the switch.

We've had previous discussions on the potential for pitting and several of us agree that it's a best practice to turn off the main breakers in your coach circuit breaker panel before connecting or disconnecting shore power (or the generator). The thought is that when the transfer switch activates the contactors while there's a load on the circuits - say from air conditioners, or water heater, that the load causes arcing across the contacts. The arcing may cause pitting on the contacts. Over time, the pitting causes an increase in resistance, leading to overheating and consequential damage.

Anyway, that's the theory that some of us have, and a best practice recommendation to minimize the possibility of damage.

The number of transfer switch failures is pretty low and so far as I know, there's never been any damage other than to the switch and the wiring inside and immediately next to the switch.

Our switch got cooked pretty bad.

 

[Jesstruckn/Jesstalkn]

Ya that look pretty bad Dan.

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[danemayer]

Even worse when it happens at 5pm Saturday in the mountains, with snow making I-70 impassable for trailers, temp at 10 (F) and overnight temps headed down well below zero.

 

[porthole]

Most of the ATS problems that have popped up on the forum were non properly secured connections inside the transfer switch.

Electrical connections such as that have a torque spec, I'd bet a 6 pack of beer that they never get torqued properly at installation.

If your RV has the gen prep and transfer switch and you have no intention of getting a generator my suggestion would be to bypass the ATS, make it a non issue.

Last time I saw a damaged ATS there was enough extra romex (surprise ) that we were able to bypass the ATS and go right to the panel.

 

[Jesstruckn/Jesstalkn]

On the Landmark and maybe the Big Horns the use a Surge Guard transfer switch which is a mild Surge protection for the RV.
I wouldn't remove it unless you really never plan to install a Gen. And if you do remove it you'd want to replace with the Progressive EMS-HW50C Surge protector.




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[divedreamer]

Sent to Ron Scarberry at Heartland Tech Support

Rig is a 2009 Big Horn 3400RE ID:203247


On Thursday, August 4, we camped overnight at Rocking A Campground (site 71) in Vernon TX. We connected through a TRC 50 AMP surge protector. I woke up about 1:30, No rear A/C. Checked and discovered that the washer, dryer, and all curb side outlets were dead. Front A/C, fridge, microwave, right side outlets were okay. Checked all breakers and all appeared okay. Following morning we spoke to a local mobile RV service who checked the power at site 71 and stated that the power was clean.


At Sam Club road service recommendation we took the rig to TexasRVGuys in Haslet, TX. They checked the electrical system completely and found that the ATS and connected wire were burned. It could be a fire hazard. They could not find the cause of the problem. They replaced the ATS and wiring. All now appears okay. I am enclosing 2 pics that they took.


We are concerned that there may be a serious hazard that could result in a fire and potential death. We are going to post this on the Heartland Forum.

If anyone else has had a similar problem, please let us know. b2healys@gmail.com

PS. We have been told that this is the first problem of this type.

Bill & Bev Healy
Cookeville, TN

I had an ATS failure this morning at 5 am. I have yet to take the PD52 lid of to see how bad it was, but it was smoking heavily and I caught it within moments of losing the heatpump. I have a 2013 Bighorn 3610RE. More later. This is an old post have there been any reports like this or recalls?

 

[danemayer]

I had an ATS failure this morning at 5 am. I have yet to take the PD52 lid of to see how bad it was, but it was smoking heavily and I caught it within moments of losing the heatpump. I have a 2013 Bighorn 3610RE. More later. This is an old post have there been any reports like this or recalls?

This has happened to a few trailers out of many thousands. The PD52 is widely used across many RV brands and is generally reliable. While alarming when it goes bad, having electrical connections inside metal boxes is to contain damage and reduce risk.

I've never heard of a recall on the transfer switch and have never heard of one actually burning down an RV. It's alarming, and it's a pain, as you can read from my old post above. If you're comfortable working on electrical, you can order one from Amazon or another source and install it yourself.

 

[wdk450]

Your high current shorepower electrical system needs regular scheduled maintenance/checking as the screws holding the wires are potentially vibrated loose by road vibrations, electrical contacts can arc and deteriorate in regular use (as detailed in previous postings). I fulltime and move on a 3 week schedule, and go through my shorepower electrical system on a yearly basis. re-tightening wire connection screws on the shorepower cord and cables, transfer switch and power protection boxes. Also open the transfer switch and power protection boxes, access the contactor relays, and file and spray with DeOxIt the contactor relay contact points best you can. Open up the circuit breaker panel and tighten ALL screws on wires. Maybe even pop each circuit breaker individually away from the breaker buss bar, spray contact points with DeOxIt and reseat the breaker maybe 5 times before moving to the next breaker.
Of course, ANY ELECTRICAL ACCESS/MAINTENECE NEEDS TO BE SAFELY DONE WITH ALL SOURCES OF AC ELECTRICAL POWER DISCONNECTGED FROM THE TRAILER.