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greaser1938 avatar image

Multiplus Wiring Schematic - vintage travel trailer...

Hey guys, I have a late Curtis Wright Clipper or an early Silver Streak. Long story... But it's currently wired up like a typical camper with a converter/charger and a 100AH Battle Born Lithium battery.

Everything works great, but I want to upgrade to a Victron 12/2000/80 Inverter/Charger that a buddy gave me after he upgraded. I'm pretty handy with my hands, but I've never enjoyed the electrical side of things. So, I've studied up as best I can and then came up with this schematic:


Could some of our more accomplished electrical guys look this over and tell me if I'm on the right track? I'm mostly concerned with wire size, fuse placement/size, etc... you know - the things that could kill me.

One thing not mentioned on the schematic. The trailer has AC. My plan is to keep it wired into the original AC distribution box and just make sure it's turned off before switching to batteries rather than running another distribution box of some kind in an already cramped area.

wiring diagram
wiringnew.jpg (319.7 KiB)
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Totally off-topic...can you tell me what software you used to create your schematic? Thanks!

4 Answers
nbezanson avatar image
nbezanson answered ·

My biggest reservation is that 15' unfused run of 8AWG wire. If a fault happens in the middle of that run somewhere, the batteries can easily set the wire on fire. I'd fuse that right as it comes off the busbar, sized to protect the 8AWG wire. (Ampacity will depend on the temperature rating of its insulation and terminations, but 50A would be safe.)

In general, any time you have smaller wire branching off larger wire, you need a fuse to protect it, since the fuse that protects the larger wire could pass more current than the smaller wire can safely handle.

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wkirby avatar image
wkirby answered ·

How old is the MultiPlus? Old VE.9bit ones won't work with the CCGX which is VE.Bus. Pop the main lid off the MultiPlus and look at the firmware number which is a sticker on the "CPU". If that number begins with 18xxyyy or lower then you are out of luck. If it starts with 19 or 20 then it is VE.Bus.

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kai avatar image
kai answered ·

I suspect you'll get arcing across the bluesea switch for "cold starts" because of DC inrush current into the multiplus, if you were using it as an on/off switch. Suggest you leave it on under normal use, and use the on/off on the multiplus front panel instead.


Re: "One thing not mentioned on the schematic. The trailer has AC. My plan is to keep it wired into the original AC distribution box and just make sure it's turned off before switching to batteries rather than running another distribution box of some kind in an already cramped area."


Can you elaborate on that a bit more? Whats currently going into the existing distribution box? The bit about making sure its turned off before switching to batteries has my interest piqued.



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Paul B avatar image
Paul B answered ·

I have adjusted the drawing to correct errors

NOTE the max current draw through the inverter is 16amps so the incoming breaker size should be reduced,


1557462941906.png (673.7 KiB)
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Don't forget to put a fuse before the busbar.

Agreed, or put the class T fuse right at the +ve battery terminal, then connect to the 250A busbar. You can split off to the DC fuse box and the bluesea switch from the busbar.

Thanks so much for this. A couple of questions:

1. I don't believe the Multiplus 2000 has an AC 2 out, does it?

2. When you say the incoming breaker size should be reduced, you mean the 30a breaker I am using right after shore power? I ask because I assumed that was the correct breaker being that's what all of the kits come with when outfitting a 30amp rv.


Thanks again!


Ryan