2 way fridge to 3 way fridge.....

[mr_clarkson]

Hi, i am currently in the process of a home build camper conversion, i have a 2 way fridge to go into it (gas and 12v) but ideally i would like 3 way!, i do have a 3 way fridge, but it is knackard, all the pipes on the back are rotten so dont want to use it! however looking at it, it seems the 240v part of it is just a transformer that then powers the same glowplug/heater element thingy as the 12v!!!

so i am wondering, if i could

A) remove the transfrmer parts from my 3 way fridge and fit them to the 2 way fridge

or (slightly prefered i think)

B) get one of those plugs with adjustable voltage, fit a socket behind the fridge and wire that in? then run the wires from the 12v battery lead, and the 240-12v lead to a 3 way rocker switch, having one side 12v one side 240-12v and the center position as OFF

would this work?


does anyone know what kind of ampage i would need to convert to?


has anyone else tried this method????


i know it would be easier to buy a proper 3 way fridge, but for one, i already own the 2 way one and cant really afford to buy a 3 way as they are alot dearer, and also i have not sseen any of the small 3 way fridges for sale like the ones fitted to old devons!

thanks for the help
jon

[Willoughby]

Hi Jon

I run my 12V fridge off a transformer when on Hook-up. Takes just over 9A. Sure it's a RM122 but would need to check.

Kev

[mr_clarkson]

thats great, thanks, are you just using one of those variable voltage plugs? if so do you have it set at 9amps? or a bit more?

cheers
jon

[VWCamperfan]

Those plugs you are refering to have a voltage setting on them, not amps. They wouldn't even come close to supplying enough amps.
A battery charger would though.

[mr_clarkson]

oh i see, sorry i thought they had amp adjustment to!!! a battery charger? as in car battery/zig?? sure it warns against this in the manual for my zig unit!

i will have a look on the bay for something, will 12v 10A be enough do you think?

cheers
jon

[Willoughby]

I have a heavy duty 230V - 12V 40A PSU in the van.

Use it to run all my 12V stuff when on hook up.

Kev

[VWCamperfan]

12 volt 10 amp will be enough but make sure this a constant running capability and not just a for a peak time of about 5 minutes!
A Zig unit is too small for this application and wouldn't supply enough power.

[mr_clarkson]

hmmmm, thanks for the advice/info

so in theory i could use a psu out of an old pc? as i am sure they have a silent cooling fan built in and are good for approx 300W / 25A i think?

thanks
jon

[VWCamperfan]

Might be worth a try. Just connect pins 14 and 15 to power up without being connected to mainboard. (Green wire to black wire).
300 watts divided by 12 volts does give you 25 amps so in theory it should cover it but PC power supplies can be funny things and may not like it!

[VWCamperfan]

Ps... Forgot to mention...!
It's not so important on modern ATX supplies but older supplies required a load to be applied across the +5v rail before they would latch on and provide a stable +12v supply.
Simply connect a 10 Watt, 10 Ohm resistor between one of the red wires and a black wire to obtain this dummy load if you have problems keeping the supply running or your voltage drops below 12v.

[Willoughby]

Trace the 12V DC lines back to the board, they will prob be on the same solder pad, do the same for 0V.

Earth case to chassis and take a chunky wire from the +12 DC to a smal fuse box then run what yu need from it.

Worth noting +12 connected to - 12 is 24Volts. The sticker on the top will cu ok.



Kev

[mr_clarkson]

thanks for the help and advice, i will have a look in the loft over the weekend as i am sure i have my old pentium pc up there, if not i will ask a few friends i am sure someone has a scrap pc. then i will pull out the psu and have a look, i'll let you know how i get on.

many thanks
jon