Proposed Update to Off-grid cabin System in VT

[LGJohnVT]

Hey, anyone interested in checking my work or giving any advice on this? I'm updating a preexisting system that is at a cabin I wont be at for a few weeks, but need to get my power set up pretty soon after arriving. The Inverters are up there. I have a manual that I've been going through to be prepared to work with them. Last I knew they were operational. The turbine and power station were operational and charging the batteries as late as October 2020, but it froze up in December and will need to be brought down and fixed at some point.

I've got the panels waiting for me and am about to order the charge controller, batteries, cables and fuses! Very excited to get this up and running.

 

[snoobler]

Welcome back!

Hope you get the Bergey sorted.

By code, you do not need a breaker/fuse between panels/SCC as the panels themselves are self-fusing. This doesn't mean you don't want one. A breaker or a disconnect switch on the main (+) line is desirable to disconnect the array. Additionally, if you ever add a 3rd string, 2S3P, you will NEED over current protection on EACH string, i.e., 3 fuses or breakers.

2awg should be fine for everything; however each inverter should get it's own supply cables and have its own fuse @ 250A (5000W surge / 24V * 1.25). You shouldn't string to one, and then just string over to the other.

80A SCC breaker should be 90 or 100A as available.

Fuses breakers should be peak current * 1.25. 70A * 1.25 = 87.5. Round up to the next convenient size. I didn't round up on the 250A because I used surge current, not run current.