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Topic: Faulty transfer switch wiring (Read 614 times) previous topic - next topic

Faulty transfer switch wiring

Here is another example of why I should always pay attention to my wife when she says "what is that noise."  It was a hum coming from one of the transfer switches at the foot of the bed.  While looking for the source I noticed that the wire connectors had pulled away from the noisy box (Lyght transfer box).  There was some dried up duct tape on each of the connectors which had pulled away from the box.  The wires were just hanging there.  Fortunately, they are solid strand and stiff. 

When I looked at the connector at the other end of the box, I saw what the duct tape was used for... to secure the wire connectors!  Real quality workmanship.  This should be a simple fix, but it would involve removing the second transfer switch which is located just above the one with the wiring problem and the hum.  We are headed for Nac on Monday and I'll have it checked out and at the very least, have the wiring fixed. 

This could have been a serious problem if any of the poorly secured wires had rubbed on the edge of the box enough to short.  I'm not sure when this box was installed.  Factory?  Replacement part?  Who knows.
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George Hatfield

  Never ever use World Line Motors of Nacogdoches for service!

Re: Faulty transfer switch wiring

Reply #1 –
Good catch George, looks like an after market job.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Faulty transfer switch wiring

Reply #2 –
Sounds like McGyver's work.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Faulty transfer switch wiring

Reply #3 –
Quote from: John44 –
Sounds like McGyver's work.
No, McGyver would be embarrassed by this-- think BUBBA!

OK, just sent this to George via e-mail:

 If you remove the cable hold downs for the cables going into the upper ATS, will you have enough slack to move it out of the way?

If so, redoing Bubbas work would be much less complex-- as you could remove just one cable (4 wires) at a time instead of having to additionally remove all the wires in the upper box to get it out of the way.

A "half as good" solution would be to just remove the "out to breaker box" cable from the upper box which should give you room to move that upper box out of the way.

Agree, if the whole upper box has to be removed, a whole another level of complexity-- thank goodness for cell phone pictures so you know all wires are returned to their original position.

Continuing with thoughts (not sent in the e-mail): Once the wires are out (do generator and shore IN separately, so no chance of mis-wiring) pretty easy to see if it was just an "oh, I forgot to put the threaded ring inside before making the electrical connections", or if the hole in the new box is larger and would not secure the threaded ring.  If the latter, a thin washer would be a reasonable solution.

As we discussed on the phone-- generator OFF, shore power DISCONNECTED, inverter OFF. On edit: will add Roland's excellent "belt and suspenders" answer (immediately below)-- even though all sources are OFF, verify with voltmeter before working on connections.

And, as has been discussed here MANY TIMES, a good idea to occasionally tighten all connections in ATS as well as breaker boxes.  Loose connections is the #1 root cause of ATS failure!

Several have asked-- why two ATS's?  One is shore power IN/generator IN and main breaker box OUT.  The second one is breaker box IN/inverter IN and "inverter powered sub-panel" OUT.  That way inverter powered sub panel circuits can exceed inverter capacity when on shore or generator.  Again, good engineering.

ON EDIT:  George just sent me a picture of the upper ATS installation.  Good job, Foretravel-- The wiring is routed such that the upper box can easily be moved out of the way to access the lower ATS.


Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Faulty transfer switch wiring

Reply #4 –
Quote from: wolfe10 –

As we discussed on the phone-- generator OFF, shore power DISCONNECTED, inverter OFF.
And I always check for voltage with a meter before I start, yes even after I turned everything off.

Roland
1993 U280 4341
2010 Jeep Liberty
The Pied Pipers

Re: Faulty transfer switch wiring

Reply #5 –
copied from Brett post
Continuing with thoughts (not sent in the e-mail): Once the wires are out (do generator and shore IN separately, so no chance of mis-wiring) pretty easy to see if it was just an "oh, I forgot to put the threaded ring inside before making the electrical connections", or if the hole in the new box is larger and would not secure the threaded ring.  If the latter, a thin washer would be a reasonable solution.

Measure the size of the connector male ends and measure the holes in the box.
Go to an Electrical Supply House, Low's, Home Depot in the electrical dept. the washers Brett is talking about are called RE washers. It takes two per hole one on each side and different ones for size of connectors and holes, and ask how they need to be installed, there is a right way and a wrong way to install. If you aren't familiar with them. Also don't for get to get the lock washers for each connector if they were not installed. With all the tape on them I am not sure what has been done to it.
Just my two cents  Good luck
Ron Clark
Sherwood,Arkansas
1999 U 295 40 foot Build # 5550
2020 Jeep Gladiator
Motorcade # 18173
FMCA # F485593