12 v compressor hardwiring

egosbar

New Member
hi all

ive posted a two links of the control panel and compressor im going to use to help with any answers

i have a ranger xls sport 2020 , the smart alternator has been disabled and i have factory fitted anderson plug to rear of vehicle for my caravan 6 b and s cable, ford have also factory fitted a anderson plug to the tub running through a redarc isolator also 6 b and s cable
im fitting a redarc 1225 bc dc charger to a lithium 100ah battery (ffrom anderson plug in tub from alternator) in one side wing of my msa drawers to run my 30 liter engel drawervfridge , i want to permanately mount a compressor under the other wing with outlet on the wing upright
i also have a kings control panel i was going to run the fridge and compressor through the rocker switches , might as well use the on off on the control panel for fridge as well i think

given the compressor power draw i was going to run through the 100ah lithium to the kings control box but im wondering if it would be better to run from the start battery either way the vehicle will be running when compressor is used, i could make an extenstion anderson to anderson and plug into the anderson plug on tow bar for the caravan and extend to a flush mounted inlet on the other side drawer wing connected to the compressor - on/off could be run either to a rocker switch on the side wing upright near the compressor outlet or on/off using the control panel

can i leave the compressor on and put a rocker switch in line from the side wing anderson plug connected to compressor, or leave the compressor on and run to the control box rocker switch, or should i tap into the on/off switch on the compressor and extend to either control box or rocker switch on the sidewing upright

any advice would be appreciated
 
Last edited:

RBJET

Well-Known Member
I'd be running the compressor from your start battery since it draws up to 45A and the Redarc charger can only supply 25A.
 

CTL

Well-Known Member
The “advertised” max amp draw of that compressor is 45 amps. I had a similar looking compressor and it drew more like 60. But anyway, let’s stick to 45. The most commonly used Anderson plug is rated at 50.
Question
(1) is all your cabling rated at a minimum of 50 amps from source to compressor, remember cabling de-rates over distance and distance is measured from source to compressor AND BACK to source.
(2) are all of your connections/joiners/switches rated at 50 amps?
 

Corndoggy

Well-Known Member
Have a read of this. Post from "drivesafe 1st September 2017 Dual Battery Circuit Safety Part 1"


I have not read it all but does give his perspective on a 50a Anderson plug specs.
 

CTL

Well-Known Member
Have a read of this. Post from "drivesafe 1st September 2017 Dual Battery Circuit Safety Part 1"


I have not read it all but does give his perspective on a 50a Anderson plug specs.
I have known Tim aka drivesafe for many years and acknowledge his experience.
However the quoted article does not cast any doubt on Anderson plugs nor their correct use in dual battery installations. The article is a warning about incorrectly sized fuses being used.
 

Rusty Panels

Well-Known Member
If your comment was directed at me, I clearly said “the most commonly used Anderson plug is rated at 50”. I didn’t say it was the only size available.
If you want genuine APs, this is my go to supplier
www.andersonconnect.com.au
No offence meant at all. I was simply showing the range of plugs and capacities available which surprised me. I have only seen 2 sizes of Andersons being used.
 

CTL

Well-Known Member
No offence meant at all. I was simply showing the range of plugs and capacities available which surprised me. I have only seen 2 sizes of Andersons being used.
Ah OK. All good. Yeah I use the Power Poles as my connections for lighter loads. Easy and simple.
 
I was under the impression the SB50 Anderson plugs are called that because they are 50mm not 50amp rated. No reason a 6B&S cable with terminals the size of Anderson plugs would only be rated to 50 amps.
Anderson's website state 120amps. Its only if connecting/disconnecting under load that its rated to 50amps.
Maybe the cheap knock-offs have a lower rating.
Egosbar
I'm in the same situation as you and my solution was to run the cables from the starter battery to a pair of heavy duty bus bars mounted under the tray, so I could split it from there to the Dc/Dc and also the compressor. Saves having to run more wiring.
 

CTL

Well-Known Member
Anderson's website state 120amps. Its only if connecting/disconnecting under load that its rated to 50amps.

And that is exactly why they are rated at 50 amps, because in the vast majority of applications, the connection is made whilst under load.
 

cam04

Well-Known Member
175a Andersen connects my jack off canopy with DC system and battery to the alternator. The cable wouldn’t fit in anything smaller. Did I mention I like cold beer?
 

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