fridge compressor power

[Phoenix of Hamble]

Over the weekend my fridge packed up.... it kept popping the correctly rated fuse...

I removed the control box, suspecting this as the problem, but was about to stick the 12V supply onto the compressor to see if that was the problem when common sense got the better of me, and I realised that I don't actually know if the compressor is 12V DC......

Anyone know what they tend to run on?

Or failing that, anyone got a spare control box for a AV12 Frigoboat system? /forums/images/graemlins/wink.gif

 

[Shalan]

We have just had a similar problem with our Frigoboat AV35. Have you got the black "Master" control box with the red and green LED's. It was the master box that was faulty on ours. Our Marine electrician was able to bypass the master box and wire directly to the conections on the compresor.

The master box outputs 12v to the compresor. I think the electronics on the compresor then hike that to 240v AC

 

[Phoenix of Hamble]

My control box just has a red LED.....

I've found a company that supply replacement control boxes, but they are £109 plus VAT and delivery.... a complete new fridge unit is around £350....

My concern is that I don't know for sure if it is the controller or the compressor..... it'd be bloody annoying to spend £135 to find out that the problem is the compressor.....

Sounds like you have a Danfoss DB35 compressor given your item code... mine is older.... I didn't check, but think its a Danfoss DB3 or DB2.5

Reading various forums around the web, the controller is renowned for failing.... so suspect i'm safe.... but budgets are tight at present!

 

[davidbains]

Whjat does the controller actually do apart from receiving input from the thermostat (which can be shorted out) and output 12 volts to the fan.? I want to know why it needs three pins!!

 

[Phoenix of Hamble]

I get the impression its much more complicated than that....

It manages the starting up of the compressor properly... it handles low voltage shut down, and with the newer ones, automatically reduces fan speeds for power consumption reduction.... I guess if the compressor is 12V DC then the rest is pretty straightforward... but don't know if it is 12v DC?

 

[Ruffles]

I'm pretty sure the compressor contains a coil rather than a motor and is driven by AC from the control box.

So you're correct to be cautious.

The Isotherm web site used to have a diagram of the Danfoss compressor. Can't find it now.