A solar inverter is earthed at three points: the chassis (safety earth), the DC side and the AC side. All three land on the inverter earth terminals and connect to the plant earth grid with copper or GI conductor, so the inverter metalwork and both circuits share one earth reference.
The earth connections
- Chassis / PE terminal bonded to the local earth bar - the safety earth for the enclosure.
- DC-side earth tying the array frames and DC equipment in through the inverter DC earth point.
- AC-side earth bonding the AC output and the downstream board.
- A dedicated earth conductor from the inverter earth bar to the nearest earth pit or grid node.
Good practice
Keep the inverter earth run short and straight for surge performance, use a conductor sized to the fault current, and add a surge protection device on the DC and AC sides referenced to the same earth. Aim for 1 ohm or less at the inverter station.
