91 CountryCoach with no 50 amp service

[lloyd&pamela]

We lost our 50 amp service yesterday and are currently running on 30 amps for half the electrical box. The 24 volt charger for the chassis batteries is flipping the breaker. I have unplugged the charger and now our chassis batteries are too low to chrank the bus.

Help. Any one with a CC and know what could be teh problem. I trouble shot the shore power with JohnW and we know it is not the box. 50/30 amps are coming to the bus but the 50 amps is being shorted by a ground fault that must have something to do with the 24 volt charger. My charger is located in the spare tire bay with a long connection from the rear to the front going through one of the prevost tubes under the bus.

Hope that helps. I have calls all day today so I will keep checking beck. Thanks guys. We are in Moab, UT now and will see everyone in OKC.

[flyu2there]

LLoyd,

First, have you tried the generator? (it should have its own starting battery or can be connected to the house batteries with the switch on the overhead panel) With the breaker open for you chassis battery charger and just to be on the safe side, the external cord disconnected, do you get the same indications with the generator running and on line? Also on you electrical panel over the door you should have an indicator for reversed polarity, that light will illuminate as soon as you plug into a box where the wires have been reversed.....is it on or was it on?

50 to 30 pretty much indicates that you have lost a leg of power. There is much more to look at but I think this would be a good starting step.......


John

[mike kerley]

Sounds like two different problems. The 24 volt chassis batteries on our 93 are not connected to the 2 chargers for the house batteries. We installed a separate 24 volt charger that only serves the chassis (engine and chassis system) when plugged in.

The 50/30 problem could be the pole, the cord or connectors or the transfer switch OR a multitude of items down stream from that. I'd check for two 120Volt legs coming out of the power cord first. The power pole/pedestal supplying you should not have a ground fault breaker, if it does, expect it to trip.

I'd start with the chassis batteries, charging them or "jump start" the coach and work from there. Will the generator start? On CC it will only "boost" the generator from the house system, not the chassis. Nothing charges the chassis system except the external charge we added and the engine driven alternator.

[phorner]

I know nothing about the CC wiring.

Just to give you another spot to check, our Liberty has 2 time delay relays inside the transfer switch. I think one is for shore power and the other for generator power. However, I believe that if one were defective, there would be no power to the bus at all.

This may have absolutely nothing in common with yours, but thought I'd pass it along as a long shot to check out.

Good luck....

[lloyd&pamela]

John, I hae not tried the generator because we have 30 amps working fine. I have two 30 amp connections outside and the rear one works the bottom breaker box which has the galley ac and the outlets I am using at present.

When I talked to OMC we discovered that the 24 volt charger was shorting out the system. When we would plug in the 50 amp line the voice would say ground fault error. I have one of the expensive 50 amp aurge protectors that JohnW recommends so I know the outlet at the campground is clean. We also tested it.

At present I have not yet tried the gen since I have a fes more conference calls today. I tried to start the bus but it will not start. I guess I will have to jump it. will the alternator charge the batteries. I have an IOTA charger. I am not comfortable working with electricity especially 50 amps.

How do you jump off a bus?

last night when we plugged in the 50 amp line to test again. The meters over the door read left 14v and right 300v. Then I turned off the ac though it was not running and the left went to normal. then cut off.

[lloyd&pamela]

Paul

We have a transfer switch with 30amp / off // 50 amp & gen. I have never opened up the switch box.

We are still getting a warning of "low vehicle battery voltage" what will hapen if this continues and how long can it be uncharged before permanently damaging the batteries. I am still tied up for two more hours today and four hours tomorrow.

We are running essential systems on either propane of 30 amps.

[lloyd&pamela]

Mike we also have a seperate charger in the front for the chassis batteries. Is there a way to see if the problem is the charger of a short in a ground line?

I will have to call someone to jump the bus since I thought I rememnber someone saying you cannot jump a bus with a car.

[phorner]

LLoyd,

Before I installed my Guest battery charger for the chassis batteries, mine went dead once, since they were not getting charged while the bus was plugged into shore power. Learned a valuable lesson there!

I disconnected all 4 chassis batteries and then charged them up individually with a standard 12 volt car battery charger. Took a while, but I got all 4 to full charge, then reconnected them, and I have not seen any adverse effects so far.

If you can get to your batteries, you should be able to charge them up this way.

However, if you suspect that your on-board charger is the culprit, I would disconnect it and leave it off.... in fact I would also un-plug it just to be sure.

If your existing chassis battery charger is causing you this problem, I would eliminate it completely from the circuit and plan on a replacement. If you can completely disconnect it from the batteries, and un-plug or disconnect it from power and your problem goes away, then all you need to concentrate on is getting those batteries up to full charge.

[Jon Wehrenberg]

I think what is critical here is having someone really familiar with the CC 120/240 power system walk LLoyd through the trouble shooting.

A major concern I have is that he has to be able to trace continuity from the power plug, all the way through to the power distribution box and its circuit breakers. The reason I backed away is because I think Lloyd described a loud "pop" as preceding his loss of 50 amp into the bus. He could have a dead short, or he could have a tripped breaker only know to Country Coach owners.

It could be as simple as a loose or faulty connection finally failing by arcing and blowing itself apart, or it could be a failed relay or contactors in the transfer switch.

Whatever it is, its impact is he has power at the power outlet in the campground, but at least one leg is not getting into the bus. His post about the charger always being on, and the chassis batteries being dead can either be coincidence, or somehow related to the issue. Lloyd needs someone with a sistership that can walk him through the diagnosis, component to component, and do it safely so Lloyd doesn't make an ash of himself

[mike kerley]

Lloyd, Your electrical is not the same as mine. I have one 50 amp connector and an automatic transfer switch. Chassis set up is most likely the same.

I'd check the four start batteries to see if they are all at full charge, one two bad or all dead. I'd disconnect the rear charger until you sort out the short in that area and get the batteries charged and the bus running. You can jump start it, but not with a 12 volt car. Once you get the bus running you can move to a different pole to see if there is a problem with the power post.

If you have good service on the 30 amp cable/switch position, but not the 50 amp, you could still have a wiring issue at the pole or the cord. Clear that first by checking with a volt meter for 120V on two legs coming out of the power cord. Then I'd check plug on the bus with the switch set to 50 amp and look for a short to ground one on of the line connectors. Everything unplugged when you do this and no generator or inverters on line..

Do the meters over the entrance door show 120 volts on each leg when on the 30 amp plug?

Do you always turn off the electric when moving the source selector switch? It could have a burnt contact.

Do you have the owners manual with wiring diagram for your couch?