Do negatives have to go to busbar or will a close earth work?

[Adventouring]

Hi all, as the title says really, I’ve had a search but seem to come unstuck.
All electrics are under drivers seat, bar EHU, 240v charger and fuse box which is in the offside rear 1/4.

My question is do I have to run the negative cable from the fuse box & battery charger to the bus bar under drivers seat or can I put the negative onto the earth point in the rear 1/4?

I have run the cables front to back but it would save running cables for no real benefit

Much appreciated

 

[Howzat]

All van earths are common, so yes, you can connect to the rear 1/4 earth point BUT you have to ensure the van body is also earthed to the on site EHU when it's live so it depends how your existing EHU is earthed. If the existing 240v stuff has it's own busbar that isn't connected to the van body then you would have run all 240 earths to that busbar instead.

 

[Adventouring]

All van earths are common, so yes, you can connect to the rear 1/4 earth point BUT you have to ensure the van body is also earthed to the on site EHU when it's live so it depends how your existing EHU is earthed. If the existing 240v stuff has it's own busbar that isn't connected to the van body then you would have run all 240 earths to that busbar instead.

Thanks Howzat!!

It’s a brand new install. Plastics consumer unit. My understanding is the 240 is earthed through the 16a plug. So the few sockets & battery charger is only live when on ehu. I’m treating the 12v and 240 as separate entities. But do you mean because the battery charger is a common on both circuit sides, that would need earthing to the ehu earth bar?

 

[Howzat]

No. The battery charger is 240v so it only earths to the 240 neg. If you had another 12v charger running from the starter battery then that could earth to the body.