Mains consumer unit earthing
When installing a mains system into a vehicle or any mobile installation, the system must be grounded/earthed to the chassis.
When we supply any mains equipment, we supply it with a 6mm green/yellow earthing cable. This is to be connected directly to the chassis of the vehicle, via a good clean bare metal connection. That's anything which is a welded part of the body work, clean the paint off, apply a conductive grease and then bolt the eye terminal on the earth wire to the chassis.
It shouldn't be earthed to the leisure battery negative, only the bodywork of the van.
Thanks for reading.