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Wiring suggestions (AWG) for my new trailer-400 watt system?

Flyfishing55

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I have 400 watts on top. I will be using a Victron Muli-Plex 1 inverter/charger, Victron 100/30 controller, 2 SOK Lifepo4 (206 amp each) and misc.-- breaker, fuses box, battery monitor... Should I go with 0 awg wire? Thanks for your suggestions, Tim
 
I have 400 watts on top. I will be using a Victron Muli-Plex 1 inverter/charger, Victron 100/30 controller, 2 SOK Lifepo4 (206 amp each) and misc.-- breaker, fuses box, battery monitor... Should I go with 0 awg wire? Thanks for your suggestions, Tim
What is the core system voltage and what is the continous VA rating for the inverter charger?
 
Additional Info: The trailer has a 30 amp system and the Victron inverter/charger is 12 volt-3000 watts. The 400 watt system is going to be 12 volt.
 
You’ll need some pretty thick wire for a 3000 VA, 2400 watt inverter. DOn’t think 0 AWG would work (Safely at large sustained loads). You may see 300 - 350 amps. Here’s the wire chart I use to size for ampacity:

D50E6FAE-72C6-4F48-A559-B73AAFB65024.jpeg
THere are other charts this one is intended for raceway cable or earth.
 
In case you find yourself ’upgrading’ down the road I might overcable a bit. Probably a little more cash now but less than buying new cable later.

Just a suggestion. If it doesn’t make sense to you don’t do it. I overcable stuff. My battery/inverter cables are still oversized, and my controller to battery charging cables (40A) have survived two panel upgrades but if I do any more I’ll need new cables. I’m glad I way oversized at version one.
 
There are 2 requirements, 1: ampacity, 2: voltage drop.
2400 ac watts / .85 conversion factor / 12 volts low cutoff = 235.294117647 service amps.
235.294117647 service amps / .8 fuse headroom = 294.117647059 fault amps.
You want 2x 1/0 cable each with 250 amp fuse(preferably with high aic rating).

For voltage drop consult this calculator https://baymarinesupply.com/calculator

Your batteries can only supply 100 amps continuous per battery.
You need at least 3 in parallel to service that inverter.

More information is needed to select wires and fuses for the rest of the system.
Are you following one of Will Prowse's blueprints per chance?
 
Last edited:
There are 2 requirements, 1: ampacity, 2: voltage drop.
2400 ac watts / .85 conversion factor / 12 volts low cutoff = 235.294117647 service amps.
235.294117647 service amps / .8 fuse headroom = 294.117647059 fault amps.
You want 2x 1/0 cable each with 250 amp fuse(preferably with high aic rating).

For voltage drop consult this calculator https://baymarinesupply.com/calculator

Your batteries can only supply 100 amps continuous per battery.
You need at least 3 in parallel to service that inverter.

More information is needed to select wires and fuses for the rest of the system.
Are you following one of Will Prowse's blueprints per chance?
^^^Do this. I have a similar setup with a Victron Multiplus II 12/3000. I have 2xSOK 206Ah batteries as well and they are not enough to fully feed the 3000W Multiplus. I am going to cable it with 2 x 2/0 in anticipation of adding another battery. The reason I am using 2/0 is because I have a lot of it. In your case, I would go with the recommended 2 x 1/0 w/ 250A fuse on each. Then plan on adding another SOK 206Ah battery to fully feed the inverter.
 
I have 2xSOK 206Ah batteries as well and they are not enough to fully feed the 3000W Multiplus.
Just in case the OP doesn't quite understand the reasoning for this statement, the inverter needs 235A (based on the calculations shown by @smoothJoey). Each SOK battery is rated to support a max continuous discharge current of 100A. With two of those in parallel you can put out 200A. Since, obviously, 200A is less than 235A your batteries can't support the full capacity of the inverter. Adding a 3rd battery would get you to 300A. Or you just need to avoid trying to pull the full 2400W out of the inverter at once. Keep it under 2000W and your batteries will be fine.
 
rmaddy: My 2 SOK are 206 amp each.
Your SOK batteries have 206Ah of capacity. That is completely separate from their 100A max continuous discharge current. A battery's capacity is independent of its charge and discharge current abilities. Those are dictated by the BMS. The capacity is a function of the size of the cells inside the battery.
 
Thanks Maddy. I might only use the microwave for a few minutes and the AC never. Hopefully I can get away with just two batteries. Corn suggests 2/0 copper wire.
 
Thanks Maddy. I might only use the microwave for a few minutes and the AC never. Hopefully I can get away with just two batteries. Corn suggests 2/0 copper wire.
For now, I am running a single 2/0 copper wire fused @ 250A. The 2/0 wire can handle that and the batteries won't put out more than 200A continuous. Just have to watch the loads when I only have the 2 batteries.
 
What kind of fuses did you get, most people will tell you to only use Class T fuses for Lithium batteries, though some will say ANL fuses are good enough (marginally), and most agree Mega fuses don't have high enough AIC to break an arc from a Lithium battery.
 
What kind of fuses did you get, most people will tell you to only use Class T fuses for Lithium batteries, though some will say ANL fuses are good enough (marginally), and most agree Mega fuses don't have high enough AIC to break an arc from a Lithium battery.
I was thinking about getting a Victron Lynx Distributor which uses mega fuses. Are you saying the Victron Distributor is no good because it uses mega fuses? That would change my mind about getting one.
 
I would suggest you do some searches here on Mega Fuse, Class T fuse and ANL fuses, there has been a lot of discussion on this topic by people that know more about it than me.
 
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