Shore Power Problem On My Coachman

[Gllash]

When I try to transfer to shore power from generator only half of the coach will work. The rear AC works fine, and some of the outlets. The forward AC will not operate and including the front outlets. The refrigerator works on gas but will occasionally transfer to AC. In the generator mode everything works great. Does this sound like a coach or electrical service problem.

I want to add that I have been connected to 50amp service and the control panel indicates 50 amps and that all circuits are powered.

Thanks for any assistance

Gary

[michaelhillhouse]

Check that the relay switch on the inverter hasn't tripped , usually there are 2 rocker switches on the inverter and if 1 trips then you will lose power to the side it controls

Regards,

Michael

[Gllash]

Maybe I'm not thinking about this correctly, very new to RVing have had my coach for a month. My understanding is shore power is introduced to the inverters to convert 120/240 to DC power then routed to the inverters which adjust the power voltage to 12volt, is that right?

Also there is a power transfer relay that transfers power from gen to shore and back again to prevent 2 separate power sources from energizing the same bus. Is it possible that the transfer switch is not transferring completely? If my thinking is correct the problem should lie in 1 of 3 possible locations, the inverter, converter or power transfer switch..please correct me if I'm wrong.


Thanks for your replay, I did check the fuses for the inverters and they are OK.

Gary

[wolfe10]

Gary,

First, since you said that the front A/C is not working, I would rule out the inverter-- VERY VERY few coaches will allow the A/C to be powered by the inverter.

Let's start by what you know does work: Since everything works on generator, the 120 VAC system from ATS (Automatic Transfer Switch) "onward" is OK.

So, the problem could be in the CG outlet, your shore power cord, wiring to the ATS or in the ATS itself.

If you are safe working around 120 VAC, pull out your voltmeter.

At the shore power outlet:

The outer straights are the hots

The center straight is neutral

The center round is ground.

From either outer to center straight= 120VAC

From either outer to center round= 120VAC

From outer straight to outer straight= 240VAC

Center round to center straight= 0VAC

If that checks out, and again you are safe working around 120 VAC, turn off all power and remove the lid of the ATS. Check for the same things there (two hots, a ground and a neutral).

Now to straighten out some terms-- assuming what you have is an INVERTER/CHARGER.

When the inverter/charger sees 120 VAC from any source (generator or shore power) it does TWO things-- turns on the charger section of the unit (120 VAC to 12 VDC) AND "passes through" the 120 VAC to all circuits downstream of the inverter or the sub-panel powered by the inverter.

When there is no external source of 120 VAC and the inverter is on, it takes 12 VAC from the battery and makes 120 VAC, but only to those circuits wired to be able to work off the inverter.

[Gllash]

Ok here is the latest... We just switched from Gen to SHORE power after running on gen for the past 3 hours and everything is now working..it must be a sticking or faulty relay..what do do think?

Thanks.

Gary

[desertdeals69]

It may be a relay in the ATS.