Below table shows some conventional and reasonable loads for you reference.
6.7.5 Earth Connection
You can additionally earth the inverter enclosure of a second earthling or equipotential bonding is
required locally. This prevents touch current if the original protective conductor fails.
Cable size: 12AWG
Connection step:
Strip the earthling cable insulation.
Insert the stripped cable into the ring terminal.
Clamp the end of the ring terminal.
Unscrew the screw of the earthling connector.
Suit the ring terminal on the earthling connector .Suit the gasket on the earthling connector.
Screw the screw of the earthling connector.