question

kyle-mccombs avatar image
kyle-mccombs asked

12/2000 Wire Size, Fuse/Breaker

Getting ready to install my 12/2000 Multiplus on my 272AH 12V battery bank, Daly 250A 4S BMS. Anyway I read on the forums here to use 4/0 wire. While that sounds great and all my Negative wire is limited to the small wire of my BMS. I also read to use a 350/400A Fuse/Breaker on my Positive side, while that is fine, Should I limit that to a 250A so I don't exceed 1C of my BMS?


What size fuse/breaker should I use?

Do I need to run 4/0 or will something smaller like 1/0 be sufficient? (<5' Run.)

MultiPlus Quattro Inverter ChargerLithium BatteryBMS
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3 Answers
rslifkin avatar image
rslifkin answered ·

On my 12/2000/80 (with a 400ah AGM bank), I had pretty short cable runs, so I went with 1/0 cable. I'm using a 200A breaker (well within the cable ratings), as that's plenty to support max continuous output of the inverter (and a very brief spike over 200A while starting a big load won't trip the breaker anyway based on its trip curve). I might lose a little bit of overload / surge capacity with the smaller than recommended breaker, but for my use, it's not a concern.

When I finished the install, I load tested with a 1500w space heater and everything worked perfectly.

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klim8skeptic avatar image
klim8skeptic answered ·

I do believe the information is available in the Multiplus 2000 manual.


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kyle-mccombs avatar image kyle-mccombs commented ·

Yes, They list it as 2/0 or 70mm2 BUT It is impossible to do so using the BMS is what I am saying?

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kyle-mccombs avatar image kyle-mccombs kyle-mccombs commented ·

And 300A Fuse, 50A more then the BMS can handle.


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kyle-mccombs avatar image
kyle-mccombs answered ·

The BMS comes with cables, <70MM2 so Naturally I would think Breaker this to 250A or so, maybe a hair less?

d-bms-4s-250.jpg


d-bms-4s-250.jpg (372.0 KiB)
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klim8skeptic avatar image klim8skeptic ♦ commented ·

Seems sensible to size the fuse at 250a.

It should not blow under regular operation of the 12-2000.

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