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Topic: transfer switch will not engage on shore power (Read 784 times) previous topic - next topic

transfer switch will not engage on shore power

On my 2004 U320, I have never had problems with my automatic transfer switch until this afternoon. I arrived at campground, plugged Progressive into pedestal, It read fine. I plugged 50 amp shore cord into progressive, and after normal wait time, the coach did not power up. I waited another 10 minutes, still no power inside.  While waiting I checked all breakers on inside panels, they were all on. I started generator, the coach powered up as always. Shut off generator, coach would not power up on shore power
I took cover off of transfer switch and took attached pictures. While coach was plugged into pedestal, I checked the power into lower switch marked shore power, it read 124 volts on both legs so I know power is getting that far. I turned on generator and watched upper switch engage- the 4 black tabs recess into switch and that load noise is made, and coach powers up. I shut off generator and the switch disengages, and tabs come back out. But the shore power does not engage??? I tried pushing the tabs in manually on the shore power switch, but they will not engage.
I can't do anymore tonight and I resume road trip tomorrow. On Monday I will be parked for 6 weeks, so I will have time and space to work on problem.
Any advice as to what I should do next? 
Thanks to all in advance
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270

Re: transfer switch will not engage on shore power

Reply #1 –

CDM,
Can you find a part number on the relay.  Maybe you can find a replacement online.  Also, do you rely on the pedestal more than using the generator?  If you rely more on the pedestal just swap the relays till you can find a replacement. From the pictures they look to be the same.  I would think you could find a replacement relay somewhere. Siemens is well known.  If you find a part number we can help you search.
John M.
P.S. A quick search and I found this.  You need to verify.
NEW SIEMENS 3RT1045-1AK60 SIRIUS 110/120V-AC 75HP 105A AMP CONTACTOR...

John & Carm Morales

"We travel not to go anywhere, but to just go.  We travel for travel's sake.  Our great desire is to move."

Re: transfer switch will not engage on shore power

Reply #2 –
I'd be cautious of changing out relays, you may lose your Gen set and you probably need it worse if traveling.  Have you checked power at the end of the cable where it plugs into the coach?    You may need to make do with Gen set and inverter until you can get the problem resolved.    Have
a great day. ----  Fritz
Fritz & Kathy Johnson
1991 36'

Re: transfer switch will not engage on shore power

Reply #3 –
When I first got home with my rig when I first plugged it in the transfer switch wouldn't engage so I engaged it manually. It failed
a couple more times and has been working since. When it wasn't working I had it on a 30 amp plug so maybe the voltage was low
as the cord is really long.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: transfer switch will not engage on shore power

Reply #4 –
I had similar problem a while back.  I DE-POWERED everything and cleaned all ATS contacts with sandpaper.  Its been working for a year now with no problems.  FWIW

jk
Jack and Cathy
1992 U280 Unihome 36' Build #4034
Cummins 8.3 /  Allison MT647/ PacBrake
Apopka, FL / Barre Center, NY

Re: transfer switch will not engage on shore power

Reply #5 –
I had a similar problem, mine ended up being the hi/lo (orange) power relay.
Dave & Danette
2005 Foretravel U270, 3620 PBLW, Build #6331
2018 Jeep Grand Cherokee
2017 Can-Am Maverick X3 RR
2016 Polaris Turbo RZR
Motorcade #17839

Re: transfer switch will not engage on shore power

Reply #6 –
On the top of the contactor/relay is the coil that activates the contactor. It should have terminals labeled A1 and A2. It will also identify the voltage of the coil.

Being careful with live voltages, you should be able to see if when you connect shore power, do you have voltage at the coil. If there is power at the coil and you don't have power across the contactor, they the coil may be bad. It could also be dirty or worn contacts inside. There are 3 sets of contacts. Both the coil and the contacts can be replaced. If you search on the part number of the contactor 3RT1045-1A you can find a number of vendors selling the entire contactor or the parts individually or as a kit. With all power disconnected you can also check for continuity across the coil terminals. If there is no continuity, then the coil is definitely bad. I don't know what the normal resistance value should be.

I am not an electrician so take my advice for what it is worth. I have experience with many similar contactors on large 3-phase wood working machines that I have. I sometimes get saw dust inside the electrical enclosure and the contacts get dirty and they won't latch reliably. Usually I can blow out the dust or run sand paper across the contacts and it works again.
Bruce & Linda
2004 U295, Build # 6268, ISL400 CAPS
2016 Ford Explorer Sport or 1985 Jeep CJ7

Re: transfer switch will not engage on shore power

Reply #7 –
Here is an update on the problem.- I got to my next stop today, plugged into the 50 amp pedestal, and in the usual amount of time, the coach powered up electrically like it always has. Although I am pleased with that, I remain concerned. On Monday when I get situated, I will check all of the items mentioned above, tighten all connections when not connected to any power, and continue to monitor the situation.
If there was a problem with the electric pedestal at yesterdays campground, I couldn't find it. The readouts on the Progressive  and my voltage meter were normal
Thanks again to all
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270