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Which pin is positive on 3 way fridge plug?

Posted: Thu Jan 13, 2011 10:07 pm
by mike_nofx
Hey all, I recently acquired a 3 way fridge which I plan to run on gas when parked and 12v only when driving.

The plug for 12v is actually a 2 pin (t shaped) plug. Can anyone tell me which is pos and which is neg?

I'm considering cutting off the plug and replacing with a standard cig lighter plug, remembering it's only for travelling I don't see any major dramas??

Any advice appreciated!

Mike

Re: Which pin is positive on 3 way fridge plug?

Posted: Thu Jan 13, 2011 11:13 pm
by watty
It doesn't matter it is connected to a heating element when on 12v. will draw about 8amps or more though, so don't leave it connected for too long with the engine not running.

Re: Which pin is positive on 3 way fridge plug?

Posted: Fri Jan 14, 2011 8:21 am
by Shadow
mike_nofx wrote:Hey all, I recently acquired a 3 way fridge which I plan to run on gas when parked and 12v only when driving.

The plug for 12v is actually a 2 pin (t shaped) plug. Can anyone tell me which is pos and which is neg?

I'm considering cutting off the plug and replacing with a standard cig lighter plug, remembering it's only for travelling I don't see any major dramas??

Any advice appreciated!

Mike
what plug is on it now? (the other end, where your going to put a CIG lighter plug)

Re: Which pin is positive on 3 way fridge plug?

Posted: Fri Jan 14, 2011 10:04 am
by kirragc
Dont run it through the cig lighter.

The three ways dont work all that well on 12V
Keep the plug setup but run a nice thick wire straight to your battery (with fuse)
This way you wont get any current loss.
The cig lighter will use a tiny wire and is all but useless.

Re: Which pin is positive on 3 way fridge plug?

Posted: Fri Jan 14, 2011 8:08 pm
by date
I am not sure of what the wiring on the 3 way fridge is, but the wiring standard for caravans and trailers is odd to say the least. Whereas on a car, most manufacturers (all that I have dealt with) use Black as the earth. On a trailer or caravan, the earth is white, and Black as the positive. So if you have a Black and WHite cabling system, I would go the white as the earth. I really should not matter because the element will be isolated from the chassis anyway, and it is purely a heater, not a motor which would run backwards.

Re: Which pin is positive on 3 way fridge plug?

Posted: Fri Jan 14, 2011 9:14 pm
by mike_nofx
It is in a caravan.
The caravan has female cig lighter sockets, with heavy cabling running to the battery.

The fridge also has heavy-ish wiring running to this type of socket:
Image

Im going to cut if off any replace for male cig lighter.

Fridge will be run no longer than 6hrs on 12V and all other times on gas.

Just need to know which wires to run as positive and which as neg.
I know someone mentioned earlier that it doesnt matter, but is there a strandard practise?

Thanks

Re: Which pin is positive on 3 way fridge plug?

Posted: Fri Jan 14, 2011 10:43 pm
by Matt_85Lux
can you see what colour wire it has from the fridge? If you do use a cigarette socket keep an eye on it the first few times using it but honestly the 2 pin plug in your picture or an anderson plug would be better suited than a ciggie socket type one

Re: Which pin is positive on 3 way fridge plug?

Posted: Sat Jan 15, 2011 1:46 pm
by MICK77
mike_nofx wrote:It is in a caravan.
The caravan has female cig lighter sockets, with heavy cabling running to the battery.

The fridge also has heavy-ish wiring running to this type of socket:
Image

Im going to cut if off any replace for male cig lighter.

Fridge will be run no longer than 6hrs on 12V and all other times on gas.

Just need to know which wires to run as positive and which as neg.
I know someone mentioned earlier that it doesnt matter, but is there a strandard practise?

Thanks

Going off the pic above, I would suggest the upper pin is positive as the red wire is shown looped through the plug at the top and the black is shown looped through the bottom. I'm no expert though.

Cheers,

Micko

Re: Which pin is positive on 3 way fridge plug?

Posted: Sun Jan 16, 2011 8:18 am
by lump_a_charcoal
MICK77 wrote:
mike_nofx wrote:It is in a caravan.
The caravan has female cig lighter sockets, with heavy cabling running to the battery.

The fridge also has heavy-ish wiring running to this type of socket:
Image

Im going to cut if off any replace for male cig lighter.

Fridge will be run no longer than 6hrs on 12V and all other times on gas.

Just need to know which wires to run as positive and which as neg.
I know someone mentioned earlier that it doesnt matter, but is there a strandard practise?

Thanks

Going off the pic above, I would suggest the upper pin is positive as the red wire is shown looped through the plug at the top and the black is shown looped through the bottom. I'm no expert though.

Cheers,

Micko
Yep, I reckon so too.