Double Check My Wire & Fuse Sizes for Tiny 48V System

[PaulLad]

This is a tiny 48V system. The reason I went with 48V is I have a gas gen and am getting the chargeverter for backup.

See attached photo for components and let me know what's wrong with my fuses and wire sizes.

500 watt inverter @ 48V = 10A = 14 ga wire & 15A fuse
20A charge controller = 30A circuit breaker & 12 ga wire
not sure how to size the wire to and from the stepdown converter. Its 40 amps so I would assume 8 ga wire but obviously Will didn't use big wire.
everything else: 14 ga wire

Thanks for any insights!

 

[time2roll]

The only real source of excess power in a fault is going to be the battery. I would tend to have a 50 amp fuse close to the battery and wire everything with #8 and not worry a bit.

 

[PaulLad]

wire everything with #8 and not worry a bit.

Isn't #8 for 40A? My inverter is 10A and the CC is 20A. That seems like a huge waste. Why would you use #8?

 

[time2roll]

Simplicity of one size. Purchase one wire roll and one bag of ring terminals etc. OK maybe two rolls to have black and red.

Marine wire #8 in free air with 105c insulation can press 80 amps. I assume all is short connections on a board so the price delta is negligible.
If everything is sized to the minimum there is greater chance of voltage drop issues. Less fuses and holders saves money and connections too.
Maybe go #10. Cost is a bigger issue when going beyond #6 or pulling wires longer distance.

 

[Zapper77]

Your step-down output...will it be connected to a 12v battery?