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No shore power to coach
Shore power to the coach disappeared tonight. Open bay one and something was clicking very loudly.
Then
a relay on my Allen Bradley computer started arcing inside. I replaced
the relay and it behaved normally. Still no shore power.I then
checked the plug and the black wire had melted and came loose from the
connector. Apparently it got hot enough to fuse itself to the common
(white) wire. However, there was no short between the white and black
wire as only the exterior coating had merely stuck together).Replaced plug but still not getting shore power to the coach. Fired up the generator and that gives me AC power.
Has anyone ever experienced this problem?
Any tips would be greatly appreciated.
BTW, I did verify that power was at the box where I plugged into.
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6 Replies
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If you have power through the shore power cord to the transfer switch box, then the next thing to verify is if it “recognized” by the transfer switch and the relay is closing to pass it through to the electrical panel.
The generator has priority and it is getting through so follow the shore power from where it enters the transfer switch box until it exits to go to the electrical panel in the coach. I would guess the problem is with one of the relays.
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I’m with Jon, I can always hear a slight “klunk” when the relay engages when shore power is applied. That relay is likely the problem and it’s a big one.
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On our Liberty, there were 2 relays inside the transfer switch, one for shore power and one for the generator. They are identical. You can try swapping those to see if that corrects your problem.
When one of mine failed, I replaced both and kept the old “good” one as an emergency spare.
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When this happened to us, it was the Allen Bradley output card that controls the transfer switch. I believe it was the second to the last module (left to right) in the A.B. rack.
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Problem solved. When I replaced the relay on the Allen Bradley computer,
I bent one of the micro-pins on the relay thus making the contactor
inoperative.The relays have 5 mini-pins and if they are not perfectly straight when plugging them into the tiny holes, they get bent.
I didn’t mention this earlier but I used a pencil to hold the
contactor shut. On the left side of the contactor is a plastic assembly
that moves in sync with the contactor. I pressed the black button in the
center of the contactor and then wedged a pencil between the plastic
piece and the housing. The black button is pulled in when the contactor
is engaged. If anyone ever has to do this, you must remove the pencil
(or whatever you use) before starting the generator. Failing to do so
could cause power to back feed into the 50 amp plug. Not good.
Thanks to everyone for suggestions and ideas.Ron
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You not only back feed power, but worse you are not syncronizing the 60HZ you get from shore power with the 60HZ you get from the generator.
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