Grounding (using a grounding rod) for two separate strings in a tranformerless inverter system (SMA)
midijeep Registered Users Posts: 102 ✭✭✭
I have a SMA system (SunnyBoy with Sunny island) with two strings going into the SunnyBoys disconnect (provided with the inverter). I want to put a surge protection device between the panels and the SunnyBoy disconnect and using a grounding rod for the grounding.
I am trying to figure out the best thing to use for the surge protection device i.e. combiner box, another disconnect and being able to run the DC ground to a grounding rod.
The SMA system does not use a ground wire from the solar panels to the inverter (tranformerless). I want to place something like the Midnite Solar surge suppressor MNSPD-300-DC in between the panels and the DC disconnect of the SunnyBoy.
Should I use a separate ground rod for both strings?
What could be a possible way to do this?
0 · Share on Twitter
Lightning wise, just a single ground rod right at the base of each box/surge suppressor is fine.
For "safety", I would highly suggest you run a minimum 6 AWG cable between each/all ground rods. That way if there is a short circuit between any of the Hot wires (whether DC or AC wiring) and metal racking, all DC / 50/60 Hz current flows between the short and the source (hopefully to trip a breaker).
Some other links: