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Fuse size for 1500W / 3000W inverter?

cyanogenic

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Oct 14, 2019
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Hi,

What amperage fuse/breaker should I use for a 1500W continuous / 3000W peak inverter?

Do I size it based on my actual loads, or based on what the inverter is capable of (i.e. 3000W, 250A in 12v)?

Note that I'm running my inverter through a 220A victron battery protect if that makes any difference?
 
What size wire? How far is the inverter from the battery?

The OCPD size is determined by the wire as well, because it needs to protect the wire and the appliance from overload/shortcircuit situations

The Battery Protect has its own OCPD built in. Usually I just use that for protection, and ensure my wire is thick enough to trigger it

AltE store has an awesome little inverter fuse/wire sizing guide: https://www.altestore.com/howto/recommended-inverter-cables-sizing-and-breakers-or-fuses-a62/
 
What size wire? How far is the inverter from the battery?

The OCPD size is determined by the wire as well, because it needs to protect the wire and the appliance from overload/shortcircuit situations

The wire came with the inverter, it's 50cm long but it's essentially right next to the battery bank.

I'm unsure of the actual size as the cable doesn't have any markings showing the AWG rating or MM2 size, but it does say 450/700V so potentially 35mm2 / 2 AWG?
 

Thanks Will.

It recommends a 250A breaker which I already have one lying around, so don't need to get anything else. I'll have to research a bit more into the wiring side of things though. AltE recommends 4/0 AWG wiring which is 120mm2 (absolutely ginormous!)

For continuous 1500W load (125A), the calculator I used shows 25mm2 is enough:
1571239307999.png

It also shows that even if I was pulling 300A through 0.5m at 1% loss, it would still only require 95mm2 or 0 AWG. So a 4/0 AWG wire seems way overkill, what do you think?

1571239161958.png
 
Thanks Will.

It recommends a 250A breaker which I already have one lying around, so don't need to get anything else. I'll have to research a bit more into the wiring side of things though. AltE recommends 4/0 AWG wiring which is 120mm2 (absolutely ginormous!)

For continuous 1500W load (125A), the calculator I used shows 25mm2 is enough:
View attachment 1195

It also shows that even if I was pulling 300A through 0.5m at 1% loss, it would still only require 95mm2 or 0 AWG. So a 4/0 AWG wire seems way overkill, what do you think?

View attachment 1194
Hi @cyanogenic where did you get this calculator ? can you put a link :)
 
Hi @cyanogenic where did you get this calculator ? can you put a link :)


 
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