question

missy avatar image

Do I ground twice?

I have a Victron multi 12 500 and I'm going to install it in my campervan.

The 16mm2 cable will run from the multi through a 100A breaker to a positive bus and then on to the 12v house batteries.

The other 16mm2 cable will run from the multi to the negative bus which is connected (earthed) to the starter battery. The negative bus is also connected to the negative of the house batteries.


Should I still connect the earth point on the multi to the chassis? If so what size cable should I use?


Thanks!

Phoenix InverterchargerGrounding
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1 Answer
Pat Davitt avatar image
Pat Davitt answered ·

The ABYC (American Boat and Yacht Council) sets the electrical standards for American non-commercial vessels (Campervans are very similar). They have discovered that in certain DC conditions related to Inverter/Chargers, which the Multiplus is, that the AC ground can be over powered and burn. They therefore have set a standard that the chassis ground wire for Inverter/chargers must be at least the same size wire as the DC positive connection to the inverter/charger and that it be wired directly to the chassis ground point.

So, in your case that would mean a 16mm2 ground wire.

Pat

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Thank you. I was worried because I had read that you should only ground the system once.

Thanks for your help.