fridge power

[tezza]

does anyone know of a decent transformer (power supply) 240v-12v that i can use for my fridge i know it takes a lot of amps because it absolutely eats the leisure battery when the engines not running, any suggestions,i know most of you will know the answer but its a muppet question from a grade a muppet so please help, ta tezza.

[AngeloEvs]

What type/model of fridge is it?

[tezza]

its an electrolux rm 122 with the gas disconnected so just the 12v works ,thanks

[Bowton Lad]

does anyone know of a decent transformer (power supply) 240v-12v that i can use for my fridge i know it takes a lot of amps because it absolutely eats the leisure battery when the engines not running

The fridge should be wired so that it only operates on 12 volt when the engine is running. It shouldn't be wired to the leisure battery.

[Louey]

I think he knows that, but can he do something so that he can use a transformer for when he has an electric hook up - I wouldn't mind knowing too

[tonytech]

A fridge will draw 8 -10 Amps, Unlike on gas there is no high, low setting so the 12V is not designed for prolonged use, it is designed to get your fridge very cold during your journey, the gas will keep it cold on the site.

T

[AngeloEvs]

The cheapest and simplest option is to remove the 12V element and replace with a 240V type (I am assuming that yours has the standard 12V element which is identical to the 240V type regards size). You can then run the fridge directly off the mains using 3 core mains cable and a fused 13A plug (and an Earth leakage circuit breaker if your van doesn't already have one fitted!) . The 240/12V power supply option is possible but you will need a Transformer with a capacity of at least 150/200 VA (watts) and mount it safely in a earthed ventilated enclosure. The 12V element will run on 12V AC just as well as 12VDC and it isn't necessary to purchase a power supply that converts to 12V DC, in any event such beasty (240V to 12V DC) will require a fan to dissipate the heat and, quite frankly, a waste of money to just run a heating element. There is no simple fix, there are solutions but none are straightforward. Alternatively, get a 12/240V compressor fridge which are far better in all respects.

[tezza]

thanks for all the info guys now i really really dont know what to do, eat out perhaps!!!!

[Nicola&Tony]

How about getting the gas connected, then it's 12v when driving and gas when parked up (with the van fairly level, so you might need a pair of those big yellow wedges sometimes). You can always turn the gas off when you go to be if you prefer as you won't be opening the fridge dooor during the night so it'll stay pretty cold until you get up again and light the gas.

Tony

[LeeCarey]

I have had a Rm122 fridge working sucessfully off the mains hookup for some time. I designed and built a power pack using A Maplin No2BA transformer. At the same time I incoporated a bead thermistor in the fridge to give temperature control. Also the control unit allows it to run on battery only when engine running. Temperature control is achieved by switching the 12v ac to the fridge element by means of a Triac and zero crossing switching IC. Thus ensuring there is no interference.

I hope this helps

[tezza]

thanks mate very helpful .which sutton , i was born in the notts variety but sutton is usually surrey!

[Louey]

I have had a Rm122 fridge working sucessfully off the mains hookup for some time. I designed and built a power pack using A Maplin No2BA transformer. At the same time I incoporated a bead thermistor in the fridge to give temperature control. Also the control unit allows it to run on battery only when engine running. Temperature control is achieved by switching the 12v ac to the fridge element by means of a Triac and zero crossing switching IC. Thus ensuring there is no interference.

I hope this helps

Thanks, but you have gone completely over my head with all that - any chance of a diagram or piccies please? - pretty please?

[LeeCarey]

Hi, My location is Sutton in Surrey. The fridge power unit was constructed inside a PC power supply unit after stripping out the guts. The mains input connector was retained and used for the new unit. My circuit is designed to maintain the fridge temperature by using a sensor mounted inside the fridge. If you did not require this addition then you could simply supply the fridge heater directly from the secondary (12volt) on the transformer. The temperature sensor and circuitry was included because our fridge tended to 'ice up'. Also included inside the unit is the relay which allows the fridge to run off of the engine battery but ony while the engine is running. Please remember lethal voltages are involved and safety is paramount. Do not construct if you are not sure of the safety issues involved. This is submitted to show how our fridge is operated and should not be construed as a recommendation of any kind. I have included links to to the photos I hope they work:
http://i287.photobucket.com/albums/ll13 ... img189.jpg http://i287.photobucket.com/albums/ll13 ... 010068.jpg http://i287.photobucket.com/albums/ll13 ... 010070.jpg http://i287.photobucket.com/albums/ll13 ... 010072.jpg http://i287.photobucket.com/albums/ll13 ... 010074.jpg Good Luck

[tezza]

thanks very much mate i get the jist of it and i hope it is useful to other members but its too complex for me!! I'll just nip out and shoot myself!!!