ATS fire caught just in time.

[jaxonwood]

2010 Landmark Augusta with an Onan Marquis 5500...
I caught a very slight whiff of electrical burn the other day and went straight to the basement to investigate further, the smell was much stronger there.
Pulling the access panel open I could see smoke coming from the ATS and discovered the 4th block melted into the plastic and the cover showing a lot of burning already. I suspect I was quite close to losing the rig that same day.
Anyway, looking into the issue I see my ATS: IOTA ITS-50R, is a discontinued unit recalled in the rigs of at least two different RV manufacturers but a call to Heartland reveals no such recall.
I understand that loose connections at the ATS are a recipe for fire but I cannot imagine nor find that this is a regular "preflight" check and I expect securing these connections is a "one and done" event at the factory given the supreme importance there.
I am searching and learning here. Does anybody have more information on this to speed me on my way to getting smart, fast?

 

[danemayer]

Hi jaxonwood,

I had a very similar experience 2 years ago on our 2011 LM. In my case, the unit failed, cutting power. So no fire. Just a difficult situation because it was a Saturday evening in the mountains at 10 degrees outside (F), with temps going down below zero.

I'm not an electrician, but I think the purpose of the metal box is to contain heat and flame.

My unit was a Progressive Dynamics PD52. I did not find loose wires. My theory about cause of failure is that pitting on the contactors over time got bad enough to create high resistance leading to excess heat.

We've had some discussions about this on the forum and a number of us have modified our setup and teardown procedures to avoid causing an arc on the ATS contactors when power is applied to the coach. I turn off the 50 amp breakers in the inside circuit breaker panel before disconnecting shore power or turning off the generator. When setting up or turning on the generator, I leave them off until after power is through the transfer switch.

Based on posts to this forum, I would say this failure is pretty rare.

 

[jaxonwood]

Okay, well, the local shop has replaced a few of those IOTA's under recall for another manufacturer. I believe it is the Progressive unit they recommended and I approved.
Thank you for the reply!