Electrics again
 

Hi all

I am in the process of wiring the van, question is, as some things (fridge, webasto heater and pump are 24v and everything else is 12v can I make everything chassis return, or do I have to make one lot earth return and the other chassis?
Idealy I would make everything earth return, but that's not the way the 12v has been wired.
I will probably make the 24v earth return, but just curious about whether it would work?

Cheers

Bruce

Years ago I had a merc 608. I had 24 vehicle and lesuire the only thing I had 12v was the stereo running from a vtronix voltage dropper Voltage Converters, battery guards & DC Power Supplies UK. all the house lighting was 24v. As far as I remember the dropper had a negative return. The advantage of the system was that I could charge both sets of batteries direct from the alternator using a boat battery switch, a very simple solution that never let me down. I realise this does not really answer your question but gives you another idea. I dont think I would mix the negatives, but I am no expert. You could call them for advice.

Graeme

Depends...

Are there separate 12 and 24 volt batteries and alternators?

No? Then is will depend on how the 12 v is tapped off the 24v. If tapped of the earthy side of the 24 v then you can use a common earth return. Note that what ever battery is supplying the 12 v, that battery will be drained more than the other battery .. leading to a battery imbalance. You can reduce this by swapping the batteries around .. make the leads long enough that you can simply swap the leads around - saves the weight lifting. You may find your present system has the 12 v supply capable of being swapped form on battery to the other ... again this is for battery balancing of charge.

Yes? Then you can wire it as a common return. No problem.

Back to earth
 

Thanks both

The 12v comes from a dropper attached to the 24v house batteries, these are charged from solar and a 24-24v charger from the vehicle batts. Sounds roughly the same as yours Graeme.

Thinking about it I can always take the 12v wires which have been run to the chassis and make a common earth back to the dropper, probably safer as the vehicle is 24v neg earth I think, will have to check it's not pos.

Electricity does my little head in!

Bruce

I would just keep the 12v side seperate....sounds like it will be easy as you already have a dropper installed. Make sure your dropper can handle the amps you need on the 12v side.

Graeme