question

Woody avatar image
Woody asked

MultiPlus ground wire overheating in an RV

I'm trying to diagnose an issue on a van that was brought into my shop. I'm pretty good on the electrical side but it's not my wheelhouse so I wanted to run this by the group for some super pro thoughts. The issue is the ground from the MultiPlus is overheating and has started to char. System is now shut down till the issue can be resolved.

Specs on the system are: Small home built camper van with 3 AGM batteries and a 2000W Mulitplus has a #14 ground from the Multiplus to the DC fuse box which in turn is run to the negative battery with a #10 wire and then to the chassis with a #2 wire. Positive & Negative from Multi are #2. My guess is that the negative wire from the multi was loose somewhere forcing current to run through the undersized ground wire. Does this sound reasonable or is there something I'm not seeing here?

Also what size should the ground be on this? I feel like #6 at minimum, possibly same size as negative? I'm also going to upgrade this to busbars so all connections are made there instead of on the battery terminals.


Thanks for the help!

Multiplus-IIAGM BatteryGroundingcampervanmiswired
2 |3000

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1 Answer
Paul B avatar image
Paul B answered ·

I suspect that you have a reverse polarity issue Ie the neutral and Active are reversed -


UNDER NORMAL OPERATION THERE should be NO current flowing in the earth circuit thus there wiring should NOT BE GETTING HOT - unless there is a fault - Very dangerous get a expert to have a look

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