Automatic Transfer switch

[kducat]

Is my automatic transfer switch malfunctioning? When I plug in the shore power, I hear a click then the shore power circuit trips. This still happens when I turn all the in the motor home breakers off. Power from the generator works fine. I can feel the box "click" when I put my hand on it when the shore power is plugged in.

[Old Bounder]

Most transfer switches are wired such that shore power would pass through the normally closed relay contacts of the TX switch (thus, NO click). It would be more common to hear a "click" when the generator activated the switch to supply gen power to the coach. There should be about a 15 to 30 second delay to let the gen come up to full speed and power prior to the click.

Since you hear a click when plugging into shore power, I suspect that, either your switch is wired back wards (which would NOT necessarily cause your symptoms by it's self) or some internal contact is welded closed. (in the gen position or actually shorted to ground)

The next most common cause could be that you are plugging into a GFCI power outlet and something in your coach has the neutral and ground bonded. That could also be in the switch.

Are you plugging into a proven good power source?
Have you used it successfully, before?

[Bjsrv]

I have had similar problems and have found the cause to be the shore power line from the coach. Be sure your power line is good from end to end. Check to make sure all connections are tight and nothing shows signs of melting or other abuse.

Sent from my iPhone using iRV2 Forum

[RJay]

I would remove the cover of the transfer switch(with all power removed) and see if there is any evidence of arcing. I would then connect shore power with the cover off to see if arcing is taking place. If you have a surge protector you might want to check that as well.

[wa8yxm]

Posibilities are:

1: Shore cord or the line inside the wall, shorted (Low probility but can happen)

2: Switch is NOT disconnecting from generator (Higher probility)

NOTE: this can be caused by "hot switching" that is ... Some things in the motor home are always on, Converter for example.. However it normally draws very little power and the transfer switch can hot switch it (Switch from Shore to Generator or Generator to Shore without unplugging from shore first) no problem.

Other things. Air conditioners for example... If you "hot switch" once too often.... Weld the contacts on the relay.. This is why you should always UNPLUG FROM SHORE POWER or better yet unplug and trip the MAIN breakers in the coach before starting or stopping, the generator.

[Donlock]

Mine clicks all the time, for years when I plug in to shore power,
never had any issues.
Don

[AZgl1500]

C A U T I O N ! ! !

If you are going to be watching an open transfer box/panel.

Please wear safety glasses.

Flying bits of molten metal can ruin your day and eye sight.

Please?

[kducat]

Thanks for all the comments.
Power source has worked in the past, but I am connecting a 50amp thru the 20 amp gfi outlet. Not trying to run anything but the outlets. Is the box worth fixing is is replacement the way to go. Coachman MH is a 1999 and I'm guessing this is the original.

[PandK]

Have you checked the 20 amp gfi outlet? If it has problems it could be your answer.

[ga traveler]

When you say the circuit is tripping, do you mean it is tripping the main breaker? I was a tech. and about ten percent of the transfer switches do energize (or click) when plugged in. This is the way they are designed. It is not a problem. Of course if the circuit is tripping the breaker, there is a problem. If you only have a short lag before the relay closes, this is normal.

[scotty2hot]

for my 2 cents worth my clicks on a 1996 fleetwood Pace arrow 37 foot
Our new 2006 Newmar doesnt make a sound when plugging in to shore power.
Check the GFI as thats happen to me at home as I run a extention cord 100 feet hope it helps

[GaryKD]

My IOTA ATS has the normally closed contacts are for the generator. When connected to shore power, the ATS must close (loud click) so the normally open contacts (shore power) can pass power to the coach.

[Go Dawgs]

I had a simular issues with my TT. I would plug into power and trip the circut box. Couldn't figure it out until I ask a friend of mine who is an electrian. He said I had one of the plugs that could be wired wrong. I started in the back and checked each plug. Sure enough it was in the front room. Replaced with new and the system worked great. Start with the wiring on your cord and trace is through. My MH does click now, but only for a quick second. I have an automatic switch.

Good Luck

[KIX]

Originally Posted by kducat

Thanks for all the comments.
Power source has worked in the past, but I am connecting a 50amp thru the 20 amp gfi outlet. Not trying to run anything but the outlets. Is the box worth fixing is is replacement the way to go. Coachman MH is a 1999 and I'm guessing this is the original.

Plug in to a NON-GFCI outlet. Betting that "repairs" the issue.