Off-grid cabin in Southern Chile

[jvierstra]

I am planning an off-grid system for a cabin I am building with my partner in Southern Chile (53.1638S latitude) and am looking for some feedback. Mostly for use in the austral summer (Nov-Mar) when sun rises at 5am and sets at ~11pm.

Basic specs:

• 48V 2380 LiFePO4 280ah battery
• Batrium BMS with relay to trip main battery/inverter breaker (run at 24V with a step down)
• Multiplus 5000W inverter 48v in 230v AC out
• 3000W solar; 375W panels 2s4p; 40V, 10amps each
• Cerbo GX with canbus integration w/ BMS
• Eventual generator for use in winter

I am a little confused about grounding the system. I currently have it designed such that the case grounds and SPDs go to two bonded earth rods. However, I have also seen it designed such that the the case grounds are bonded to the negative battery terminal and then to earth ground (seems to be what Victron recommends). What is the difference, if any? I should mention I will be adding a current leakage device (GFI) and a surge protection to the AC side and those will be bonded to the DC ground.

I haven't decided if the Cerbo GX should be powered at the positive bus bar or directly from the battery alongside the BMS.

 

[WYtreasure]

Awesome 1st post. Welcome to the show.
I don't have an answer to your grounding question but will help build everything if you get me and a few fishing poles there.

Why the shunt when you could do this instead?
droking.com/Bidirectional-Volt-Amp-Meter-LCD-Display-Multimeter-with-Hall-Sensor