Burnt AC Transfer Switch, Wires

[jlandon13399]

Set up camp in Denver June 15th. On June 16th late PM I noticed a bad electrical smell in my motorhome. After searching I found the AC transfer switch burnt and several wires and insulation on the top third of the switch were burnt. I immediately disconnected the AC shore power, turned off all breakers in the AC panel and kept looking for additional problems. Questions: has this happened to anyone out there? What could have caused this after 24 hours set-up with no problems?

[wolfe10]

The most common cause of overheating in an ATS is a loose connection. A loose connection= resistance= heat. Heat degrades insulation and also the copper of the wire= more resistance.

Once a year it is a very good idea to check both ATS and 120 VAC breaker box for any sign of overheating and also check the tightness of all connections. A very worthwhile 15 minutes.

[dickandlois]

Jack, you might want to contact the coach maker and see if they can supply you with the wiring diagrams for the circuit referencing while repairing and trouble shooting.

One should take a number of pictures and some good notes when there is a number of loose wires.

Rich.

[wolfe10]

Are the burned wires inside the ATS or wires outside it from generator or shore power or to coach main 120 VAC breaker box?

[jlandon13399]

Brett and Rich,

Made it back to Lazy Days in Tucson. All wires were connected and not loose. The switch wires were burned on the top third, and the switch will have to be replaced. After I get a final report from Lazy Days I will let you guys know. Thanks for the advice.

[billbaldwin]

If you buy a new ATS, my ATS and Surge are a single unit.

Works great. Always good to go for a twofer.Mine is made by Progressive Industries Inc

[jlandon13399]

Bill,

I will ask Lazy Days about this when they call me with the pricing to repair my unit.

[ShapeShifter]

_{Was this an IOTA transfer switch by any chance? Many were recalled by Monaco due to exactly the situation you are describing. The wires and contact blocks in the switch are much smaller than some other brands, and are prone to overheating.}

_{When you replace the switch, go with a more substantial brand. IF you just open up the cover and look inside, the difference in the size of the components is very obvious. Small wires and contact blocks mean more heat and more problems. while larger wires and contact blocks can better handle the current without overheating.}

[jlandon13399]

Yes it is an IOTA 50 amp transfer switch. I will let the repair facility know. Thanks for the heads up.

[wigginsjsr]

I can't find where Progressive Industries makes a transfer switch. Could only find one made by Progressive Dynamics - seems to be different company.

[jleamont]

This happened to us on our old coach, it was low voltage from the tower caused the amperage to spike melting my transfer switch wiring and Neutral Buss bar. I (got this from an electrician) I took the unit to our local RV dealer for other work and had them look over the wiring and make the necessary repairs.

They told me they see this all the time and to buy a surge protector that monitors this situation and will shut the coach down in the event it happens again. I took their advice and I have had my fair share of power outages since with the surge protector cutting the coach power.

[jlandon13399]

I purchased a Progressive Industries EMS-LCHW50 wired surge protector with low voltage protection. Lazy Days has wired it in my motorhome. I am now waiting for a new cord reel. The one ordered was the wrong size so another three weeks to get the proper one. I hope to finally get my coach back by the end of August after dropping it off June 18th!!