Mounting a circuit breaker

G'day!

I have a 2008 GU Cab/chassis with a canopy mounted on the rear. I have removed all the old/dodgy wiring in the canopy and wish to upgrade the whole canopy electrical system.

My first problem is to find a place to mount the circuit breaker (a US made WiseOwl 60amp unit) near the starter battery. Has anyone mounted this type of unit before and, if so, where. Also any photos of bracketry used will be gratefully accepted.

I am installing 2 x 135ah AGM batteries, a Projecta DC/Solar charger, and intend to run all my lighting, fridges and chargers through a 12 port Narva distribution box.

I want to run the power from the engine bay to the canopy on the driver's side = shorter run of cable.

Any assistance will be greatly appreciated.

Many thanks

Creosote

I have a couple of similar circuit breakers in my canopy. One is screwed to a block of plywood which is simply glued to the inside of the canopy, the other screwed onto a thinner ply cover which has other wires behind it . Attachment 82402

Attachment 82401

Thanks Cuppa. My main problem is trying to find a good spot close to the +ve terminal of the starting battery. DO you have any ideas that might help? I'm pretty new to this 12 volt stuff so any help you can offer will be greatly appreciated.

Quote:

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Originally Posted by creosote54

Thanks Cuppa. My main problem is trying to find a good spot close to the +ve terminal of the starting battery. DO you have any ideas that might help? I'm pretty new to this 12 volt stuff so any help you can offer will be greatly appreciated.

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You should be able to find a spot on the firewall there somewhere? You do want it as close as possible to the battery but a short run to the firewall will be okay. Just keep it well insulated.

Just be aware that these units are not waterproof despite what they may claim. Either have then up high out of the way or cover them somehow. I have one mounted flat behind the second battery and about level with the top of it and after a failure due to water I made a 3D printed clip-on cover to fit over it. No problem since.

I have a L bracket tek screwed in next to where the battery sits.
Attachment 82432

Thanks Mudski for the photo. I reckon that'll be just the place.
And thanks also to 0-TJ-0 and Brissieboy for your information.

Well, it's done and thanks again to those who offered information and assistance.
Another request. I would like to know what would be the correct gauge of wire to use to connect from the starting battery to the CB, and from the CB to the tray on the rear of the truck? As mentioned above the power will be going into a Projecta DC/Solar charger.Attachment 82459Attachment 82460
P.S. The large red cable in the photos is the power cable for the winch.

I would use 25mm but 16mm would probably get it done. Voltage drop at 60A is a concern.
I have just upgraded the 10mm I originally ran to 35mm. My air compressor is now a lot faster and I get no voltage drop at all to my oven which was under performing before.

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Great job nice and neat , gotta be happy with that.
What you dont want is voltage drop, do some maths
maybe 25mm like Winnie suggested.
remember all these members have already done this so
they know whats right and what works
@Cuppa has an extensive electrical set up in his canopy setup.
Check out his build thread youll find most of your answers there
Im sure, or just ask, easy as, TD

The chart in this link is an old favourite of mine. It is for sizing solar cables but works just as well for any other cables where you wish to size them to minimise voltage drop. The chart is based on the premise of restricting voltage drop to 3%. In the case of creosote 54's supply cable from crank battery to the dc to dc unit in the back of the vehicle you could use the max current of 60A (size of the CB & the total length of cable to see what the chart suggests the size of the cable cross section should be. In reality you can go smaller, because the dc to dc unit will compensate for voltage drop by increasing the voltage. (at the expense of lowering the current- amps). Minimising voltage drop in the cable will make the set up as efficient as it can be, & thus make the charging process as quick as it can be (useful for when you want to get max charge into the batteries but are not driving for long) but I wouldn't get too hung up on it, & suspect that Winnie's suggestion of 16mm2 or 25mm2 would do the job just fine.