Earthing and surge suppression in high risk zone

[cansel]

Hi All,

I have a 3.3kw array split into 3 x 1.1kw series in parallel which then tie into a surge suppressor which is connected to a physical earth pit a few feet away on a 6 gauge copper cable. The live cable runs 120ft to a 50 amp breaker and then to the inverter which is connected to another physical earth pit a few feet away. Then the 220v ac power runs to the main breaker in the house which in turn is connected to a third physical earth pit about 25ft away. I was advised not to ground the solar panels as it will attract lightning and should instead install a lightning protection rod on a pole connected to a separate earth. Where would be the best place for this rod?? A high location? How far?

I also read that I should install two surge suppressors before the inverter due to the long cable run but was advised against it by the local engineer who sold me the breakers. Should I install the second surge suppressor? Where should it go? Before of after the breaker?

The ac cable run is about 80ft from the inverter. Should I install two surge suppressors on that line? One close to the inverter and one before the main breaker?

Given that I'm in Yucatan and the lightning is very intense from June to October, should I install two lightning arrester rods?

Any help I can here is highly appreciated as I'm terrified of lightning strikes. Is my setup overkill or could it attract lightning? I have 6 gauge cable connected to the earth pits.

Thank you!

 

[AntronX]

I was advised not to ground the solar panels as it will attract lightning

Grounding panels will not attract lightning any more than they already do.

and should instead install a lightning protection rod on a pole connected to a separate earth.

That may divert direct strike from your panels if lightning rod height is much higher than panel array but ground potential surge will kill your inverter due to having separate unbonded grounds.

I also read that I should install two surge suppressors before the inverter due to the long cable run but was advised against it by the local engineer who sold me the breakers.

Bad advice. You should install surge protectors on PV input of inverter and AC in/out tied to the same ground point. Install surge protector on panel combiner bonded to panel array ground as well. Use #6 wire to connect all ground pits together.

 

[cansel]

Thank you! My next question is how do I wire a split phase spd. I have an ac spd rates for 275v but it has two L inputs. The DC spd is straight forward as it is labelled with plus and minus but the AC one only has 2 Ls. Would I need a special sod for split phase or will the one I have work? Is there a wiring diagram i can refer to?

 

[AntronX]

what voltage is your inverter?

 

[cansel]

what voltage is your inverter?

6kw

 

[400bird]

what voltage is your inverter?

6kw

V is for voltage
W is for watts, the k on kW is for thousand

I'm not grounding or lightning expert, but with everything I've read, you have too many separate ground "pits"
The consensus here is that you should have a single ground location and run ground wires back to that single location.

 

[cansel]

Thanks. 48v, sorry. I was told that due to the large distances (with hills) between the solar panels, inverter and house it would be best to have more than one earth pit.

 

[400bird]

120 feet isn't that far for electricity.
There are other members here with more grounding and lightning experience than me, hopefully they'll chime in.