Lost partial power - 2015 Momentum 350m

[Tim & Connie]

The fridge should run off of the propane, as long as your battery is charged enough to provide power to the controls for it. If the battery is down too low, the propane side of the fridge will not work.

With all the fun I have been having chasing the electrical problem, haven't checked the status of the battery, could be run down. I'll deal with that next. Got all the food out of the fridge and stored in someone else's fridge, so hasn't been a priority yet.

[Hoopy Frood]

FWIW, I had a toyhauler that had a recall for potentially faulty Iota Automatic Transfer Switch. This was a few years before your 2015, but something to consider.

[CoChris]

Anyone have a guess on why it failed? My best guess is a lose lug, but don't much about transfer switches.

My guess is poor assembly resulting from
1) Lug not tightened properly or
2) Wire not cut straight and fully inserted under lug or
3) Insulation not completely stripped and partially under lug

I have seen all of these occur at one time or another. GD (and all manufactures) electrical work is very poor at best.

I have also seen (on one cheap contactor) where there was plastic film on the contact side of the lug(s). I assume to keep them clean during shipment, but it was never removed during assembly (this was on some Chinese machinery, not a trailer).

Or it could be something else entirely.
You are wise to replace the entire assembly. For the cost, it is a good move.

Chris

[xrated]

There is a good chance that the wire came loose in the lug. Once that happens, things start heating up when under a load. At some point in time, it looks like there was an arc flash that started melting the insulation on the neutral wire and once that happens, it becomes a dead short from the line side to neutral. The transfer switch will experience some vibrations simply from the fact that the contactor picks up and drops out every time you plug into shore power and then unplug and travel. That constant pick up drop out of the contactor over time can cause the screw terminal to loose up a bit...it doesn't take much. Every time I've ever done a new installation and torqued the terminal down to spec, I try to grab the wire close to the terminal and wiggle it a bit...back and forth, up and down. After doing that, you can usually tighten the terminal screw or bolt a bit more....sometimes a 1/2 to 3/4 of a turn on some of the larger wire.

Once you get the new one installed....do the wiggle thing on the wires and check your terminals again for tightness. Then, a month or so after the install, remove the power and go back in and check them again.

[Malco1]

You have 1 leg out. Probably at the pedestal.

That is what I was thinking.

[IBEW Sparky]

@xrated

Great explanation!

[IBEW Sparky]

Your suggestions were helpful. Plan on cutting back the ends, insulation on a couple of wires melted back a inch or two. One wire cut itself back, melted at the lug. I will replace the whole switch, no way to rebuild that melted mess, and not worth the risk for the $200-$250 a new one costs.

Anyone have a guess on why it failed? My best guess is a lose lug, but don't much about transfer switches.

I agree that it was probably a loose connection which can be caused by several things as others have stated. You're going to have to cut back more than an inch or two on that burnt cable assembly. The excessive heat that was present on that wiring has most likely damaged the insulation properties of those conductors. Hopefully there is a decent amount of slack in that wire somewhere between the transfer switch and the other end of that cable assembly. Keep cutting the wire back and striping the insulation off of each conductor until you have clean BRIGHT shiny copper wire without any darkening or discoloration. If you have any discoloration on that wire there is going to be loss of insulation value as well... possibly leading to another failure down the road. You don't really need an entire new transfer switch as that 3 pole contactor can just be replaced by itself.... saving you time and money.