I'm putting together an off-grid PV system for a small barn[ Northumberland UK]. [no grid feed] 've been running a 100amp board consumer board [no rcd, a range of amp MCB's] using a generator for now. I've assembled various pieces and looking at putting them together. Here is my practice/mock up board in my garage. This will be set up on a stone wall.
Top left, you can see a Victron smartsolar MPPT 250/100-Tr charge controller. On the right a Quattro 48/8000/100. It's over spec'd for my needs really. Will at times be running a good load though. There's a 32amp solar cable switch to isolate the PVs [see below]. You can see bottom left a BMV -712 500 Amp shunt, with a lead going to the batteries -ve. The batteries [see below] positive 4AWG cable comes into the mega fuse holder leading to a 300amp on/off disconnect and then the Quattro. The fuse for the +Ve cable from the MPPT is 125amp [from reading the manual I think that's correct]. The battery +ve fuse is 250 amp. The cables are all 4awg [25mm] in size, and I've doubled them up for connections to the quattro, keeping lengths as short as possible etc.
All this will be controlled via a CCGX panel, but I've left the coms leads/connectors off for now.
For Solar panels I have 8 of these:
Voc of 39.8v and ISc 11.06a with max series fuse rating of 20amp. These 8 panels are connected with 2 banks of 4 panels in series, then the 2 series in parallel. The +Ve solar cables from each series have a 20amp fuse in line. Total max is 8x345w = 2760 watts [room for expansion if needed!]
The batteries will the 4 x US3000c pylon lithium batteries in parallel = 3.5x4 = 14kwh when full.
There will be a Type B 64amp RCD between the output from the quattro to my main consumer board.
I had a 10kva stephill diesel generator I'll be setting up for the CCGX to switch on when batteries are getting low etc.
It's a windy location especially in winter, so will be ground fixing the panels. I've struggled to find sturdy mounting frames so have designed my own from 48mm galvanised poles and brackets. There will be 4 of these frames with 2 PV to each. All facing south. Poles set in concrete.
I'd value any questions or comments on how I am doing setting this system up so far. Open to suggestions, not having put a system together before.
One question I have is the fuse amp that I should have in battery +ve lead to the Quattro. I have a 250amp in there, but the battery cables are 4AWG so surely a 125amp would be better there?
