What Size Circuit Breaker from Generator

crop duster-ClassB

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Oct 14, 2019
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9
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Colorado
I'm trying to track down why my 2010 Great West Van on a Ford chassis is not charging the house batteries while the van is running. It's new to me and I'm not sure it has the capability to do it but I feel like it should. I didn't notice a cable coming off the engine battery running to the house batteries so I'm kind of stumped.....

Anyways, as I was poking around underneath I found a loose wire coming off the two post circuit breaker that I think goes to the 2800 watt onboard generator and I'm not sure if anything else. I went to tighten it and the circuit breaker pole broke off. The entire breaker is quite corroded and rusty. I tried to loosen the opposite side to replace the breaker and that pole broke off as well.

Does anyone know what size circuit breaker it would be? There are no markings left on this one and I have no idea what is the correct size.

Thanks
 
I would expect it to be 50 amp DC but some brands used 30 amp. There should be one at either end of that cable to the battery. I’m not familiar with your brand but you can replace with the automatic reset type or the manual reset with a button.

https://www.amazon.com/Amp-Automatic-Reset-Circuit-Breaker/dp/B006PJI1YW

If it is greater than a 10 gauge wire use the 50 amp.

Can anyone explain what information is conveyed by the one copper terminal?

The house battery should go directly to the generator without going through a circuit breaker. The alternator should go to the house battery through two circuit breakers, one at each end. I suppose some only used one. I haven’t found the second one on my Roadtrek
 
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Thank you for the info on the circuit breaker.

It appears that its purpose is for charging the batteries and starting the generator. There are two wires on the aux side post and two wires on the battery side post. One wire on the battery side goes from the post to the battery. The other wire on that same side goes into the generator. I found the generator will not start without this wire connected to the battery (the wires are still connected to their respective post as both posts broke off from the body of the circuit breaker). Once the generator is running I'm getting 14V on the aux post. There are two wires on that aux post so I assume one comes off the generator but I'm not sure what the other one does. When the van is running I'm not getting any power to that post (trying to track down why the house batteries are not charging while the van is running). So this is all clear as mud...?


Maybe I'm looking in the wrong spot for my charging issue. Instead of a wire coming off the coach battery running to the house battery you're saying there should be a wire coming off the alternator going to the house battery (or in this case circuit breakers)? It's a mess of wiring in the back under the coach and it's been difficult trying to trace wires.
 
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Thank you for the info on the circuit breaker.

Maybe I'm looking in the wrong spot for my charging issue. Instead of a wire coming off the coach battery running to the house battery you're saying there should be a wire coming off the alternator going to the house battery? It's a mess of wiring in the back under the coach and it's been difficult trying to trace wires.

Alternator should go to the center tap of an isolator or separator. The other two posts go to the chassis battery and house battery respectively. The term coach battery is usually used for the house battery. The house battery line then should go through two circuit breakers, one at each end, to the house/coach battery.

The generator generally needs a direct line to the house battery because circuit breakers have trouble with the starting current pulse. Detach that cable from the battery before playing with it unless you want to to see some welding.

I think a separator only has two posts. I don’t have one. Anyone else is welcome to jump in here.
 
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I don’t know how a GWV is wired but in some vans the alternator power line goes to the battery side of a battery contactor which connects to the battery. The contactor is inside the coach as is the second circuit breaker.
 
My last van was 2000 Pleasure Way and the isolator was clearly visible in the engine bay. I can't find anything of the sorts on this van. I've crawled all over it and I've come up empty handed.

The alternator has one large wire coming off it and that wire goes into the wire loom that goes directly to the battery as well as the starter. The chassis battery only has two positive wires coming off it. One is the wire that goes down to the starter as well as splits and goes to the alternator.

The other wire goes under the battery tray and I can't trace it. The wire loom that was used looks like stock Ford though.
 
Someone with a GWV will have to answer but I would mount an isolator on your firewall, run the alternator wire to the center tap, and leave the battery/starter wire where it is. Add a wire to the chassis battery from the isolator. You would want at least 4 gauge welding cable for flexibility.

The other post of the isolator run at least 4 gauge wire to a circuit breaker nearby then 4 gauge to the house battery or battery contactor through another circuit breaker nearby.

You will charge your house battery then.

The fact that the alternator went straight to the chassis battery tells me that it was never intended for house battery charging or that line was removed before you got it.

This doesn’t explain what the disintegrated circuit breaker is doing. I just haven’t seen one in line with generator starter current. Maybe it works. Maybe there is another line directly from the generator to the house battery that you haven’t found yet.
 
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