I've been working on the wiring plan for my Ford Transit van conversion. I'm not an electrical guy and I've been following on the coat tails of others in developing this diagram. The unique part of my plan is the addition of a 3-way switch after the SCC to be able to select solar charging of the house batteries OR the start battery (mainly for when the vehicle is sitting for a long period of time). However, this benefit will come with the inconvenience of having to reconfigure the SCC from charging a lithium battery to an AGM battery. I believe this set-up will work, but I haven't seen it done before. Anyway, any overall input or guidance to obvious issues in the diagram would be much appreciated.
How's this diagram look?
- Thread starter JRG
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John Frum
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The only thing I see is that you should have a 250 amp fuse on the inverter circuit.
2000 ac watts / .85 conversion efficiency / 12 volts = ~196 dc amps
~196 amps * 1.25 fuse headroom = ~245 fuse amps
Good drawing!
UPDATE:
possibly swap the terminal fuse for a class-t in front of the battery.
Maybe you can find a charge profile suitable for both the starter and house batteries.
You are right on the edge with your wire from the alternator might want to bump that up a size.
2000 ac watts / .85 conversion efficiency / 12 volts = ~196 dc amps
~196 amps * 1.25 fuse headroom = ~245 fuse amps
Good drawing!
UPDATE:
possibly swap the terminal fuse for a class-t in front of the battery.
Maybe you can find a charge profile suitable for both the starter and house batteries.
You are right on the edge with your wire from the alternator might want to bump that up a size.
Last edited:
Thanks! I'll look at those changes.
If the inverter fuse is 250A, should the main battery fuse be increased by a size (275A)?
OK, I'll change the 2/0 to 3/0.
What's the advantage of a Class T over a Terminal fuse? Comparing them, looks like the Class T has a longer trip delay time. The 300A Class T blows at about 60s at 200% load (for example). The terminal fuse blows at about 8-10s at 200%. What's an optimum time delay in an application like this?
John Frum
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I guess it depends on the class t but most of them are quick blow.
The class t can interrupt 20000 amps at up to 125 volts.
The terminal fuse can only do 10000 amps at 14 volts.
A lifepo4 bank can deliver stupid amounts of current into a dead short.
I'm not sure how much current but it would be a bad day if you had a sustained arc over a blown fuse.
I like terminal fuses but I bought a class t fuse for my 280ah@25.6 volt battery.
Instead of the On/Off switch between the solar panels and the solar charge controller I would use a DC circuit breaker. That gives you some protection while still allowing the On/Off action.
Good idea, thanks.
This information gives me another factor to look at when choosing fuses. Thanks!
mikefitz
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It's a circuit breaker. They trip on excess current.
LMGTFY - Let Me Google That For You
For all those people who find it more convenient to bother you with their question rather than to Google it for themselves.
mikefitz
Solar Wizard
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How can a solar panel deliver current in excess of its design short circuit current?
I have seen breakers or fuses suggested many times but cannot see, for a single string of panels, how they will offer over current protection. I can see the isolation effect of a breaker when used as a switch.
Mike
