Trailmanor AC failure: Faulty Wiring

[FlyboyTR]

Trailmanor AC Failure.... PROBLEM FOUND!

After hours of trouble shooting the air conditioner and controls, we ended up with the belief we had a neutral wiring problem. This turned out to be the case! It is amazing that usually the last place you look is where you find the problem..........ironic isn't it? LOL

I have also posted this on the Facebook TM Fans group but wanted to share it here as well.

All Trailmanor owners should inspect this failure point!

https://www.youtube.com/watch?v=2HXcMXTZ2QQ

[Bill]

Kind of a tricky find, since the neutral was good to all the rest of the trailer.

The use of electrical tape - the devil's own invention - tells me that the box was re-wired by an untrained amateur, not by any kind of pro in the factory. And that suggests to me that he simply poked the wires straight into the wire nut and twisted the nut, without pre-twisting the wires. A common error, and you experienced the common result. Again, good find.

Bill

[FlyboyTR]

Thanks! I am frequently amazed (and concerned) about "how" many folks use wire nuts. As you noted...there is a right way and a wrong way!

Travis

[Deb Mac]

Great detective work Travis! I will take a look at mine while I'm over there today. Not having any electrical issues at all, but then again, neither were you.... until you were.
Also another good incentive to have a surge protector on your 30A line at the campground.

[FlyboyTR]

Thanks! I'm still scratching my head on the surge protector thing. For 47 years I have never used one. I purchased a surge protector a few months ago. It didn't seem to do anything to help me. BUT... this is/was an unusual situation. I will continue to use the protector with hopes that it may help save me from something in the future.

Let us know if you find anything out of order in the box!

[Bill]

My guess - and it is only that - is that the failure had nothing to do with an electrical transient ("surge"). Instead, I'm thinking that the wire nut on the neutral wire was stuffed into the connection box open-end up. That is a big no-no for any potentially water-exposed work involving wire nuts - including any wire nuts used on the electric brakes, by the way. Water collects in the wire nut, corrosion begins on the wires and on the metal spring in the nut. As the diameter of the wires and the spring get smaller, they lose physical contact pressure, develop resistance - and the high current drawn by the AC at startup burns up the connection.

Just my thought - but all the signs point to it, especially the incineration of all the parts. Since the transient (if any) didn't affect anything else in the camper, I'm having a hard time putting the blame on a surge. And the fact that a circuit breaker didn't trip suggests that there was no actual surge. Assuming I am right, a surge protector would not have helped at all.

Bill

[FlyboyTR]

Originally Posted by Bill

My guess - and it is only that - is that the failure had nothing to do with an electrical transient ("surge"). Instead, I'm thinking that the wire nut on the neutral wire was stuffed into the connection box open-end up. That is a big no-no for any potentially water-exposed work involving wire nuts - including any wire nuts used on the electric brakes, by the way. Water collects in the wire nut, corrosion begins on the wires and on the metal spring in the nut. As the diameter of the wires and the spring get smaller, they lose physical contact pressure, develop resistance - and the high current drawn by the AC at startup burns up the connection.

Just my thought - but all the signs point to it, especially the incineration of all the parts. Since the transient (if any) didn't affect anything else in the camper, I'm having a hard time putting the blame on a surge. And the fact that a circuit breaker didn't trip suggests that there was no actual surge. Assuming I am right, a surge protector would not have helped at all.

Bill

I am in agreement with you. That connection was a weak link and when the power went on/off/on/off...flash/flash/flash (then back on) I know the compressor was locked when it tried to instantly restart. Then multiple assaults just multiplied the problem and the connection finally failed.

Regardless...it should make everyone want to take a look down there! Thanks again for your input! Appreciated!

[[email protected]]

Originally Posted by Bill

Kind of a tricky find, since the neutral was good to all the rest of the trailer.

The use of electrical tape - the devil's own invention - tells me that the box was re-wired by an untrained amateur, not by any kind of pro in the factory. And that suggests to me that he simply poked the wires straight into the wire nut and twisted the nut, without pre-twisting the wires. A common error, and you experienced the common result. Again, good find.

Bill

Unfortunately I also found a wiring problem at battery when I changed out glass fuse for 30 amp spade type. Wires at wire nut were only stripped about 5/16” and wire nut did twist wires. Trailer was only a year old. I don’t believe any owner did any changes. I was really disappointed in what I saw. 2007 2720SL

[makriegz]

Thanks for this post!! I have been troubleshooting my AC and electrical setup for week now. And thankfully, seeing your post and video, I was able to resolve the issue pretty easily.

I am parked in a friend's driveway, plugged into their house's external 15A plug with GFCI. It's been plenty to run AC for the last month. Then last week, on a particularly warm day (for Seattle), the house's GFCI tripped. We reset it, powered up the AC again, and within a few seconds it tripped again. From that point on, I had a ground fault.

The main difficulty I had, while trying to research this online, was that most resources say that in order to diagnose and locate a ground fault, flip all the circuits to off, then plug in the RV, and flip on one breaker at a time until the home's GFCI trips again. But, that wasn't my situation. Even with all the RV's breakers off, the home's GFCI would immediately trip when I plugged the RV in.

Over time, I learned some basic lessons of electrical wiring. Like, the breaker in the RV is only on the hot line, so the breaker being on or off won't affect a ground fault, which is an unwanted connection between neutral and ground.

This also meant that, somewhere in all of the circuitry, something had probably overheated and melted, because my setup went from working to ground faulted. But I struggled a lot on how to locate the ground fault.

In the meantime, I plugged the RV into a non-GFCI circuit in the house, and was able to run the AC for the last few days while I continued to research the issue. (In hindsight, this may have been a dangerous choice...)

Today, I found this video posted above. So I disconnected from shore power and battery, got into the box, and discovered that I also had a screw cap burnt off. Plus, all of the cords were wrapped up together in 1 was of electrical tape.

So I cleaned up the cords as best I could. I then did some continuity checks between the shore power cord prongs and the exposed wires. My tests showed that all 3 prongs/wires (hot, neutral, and ground) were separate again. So I plugged the RV back into the house's external GFCI circuit, and the GFCI didn't trip!! Problem solved.

Long journey, but thankful for this incredible forum.

[FlyboyTR]

Originally Posted by makriegz

Thanks for this post!! I have been troubleshooting my AC and electrical setup for week now. And thankfully, seeing your post and video, I was able to resolve the issue pretty easily.

Long journey, but thankful for this incredible forum.

Excellent. I am glad you found my video beneficial. Thanks for the kind words!

Travis