DANFOSS BD35F Fridge Controller

[Lone_viper]

Hi all,

On the back of the controller there are all the spade connectors.... + and - are obvious, but does anyone know that the letters mean.....

F D C P T

I realise there are diagrams, for for C and T for example, which way around do the thermostat leads attach? The diagram isn't obvious on polarity or does it not matter?

Kind regards

 

[GHA]

https://assets.danfoss.com/documents/30339/AN024286435171en-000601.pdf


For a mechanical thermostat don't think it matters which way round, but C is ground( batt negative) , T feeds 5v , attach that to ground ant the fridge will run.
You can actually control the speed of the compressor by altering the current flow out of T to ground with some resisters.

 

[Graham376]

Hi all,
On the back of the controller there are all the spade connectors.... + and - are obvious, but does anyone know that the letters mean.....
F D C P T
I realise there are diagrams, for for C and T for example, which way around do the thermostat leads attach? The diagram isn't obvious on polarity or does it not matter?
Kind regards

Doesn't matter, the thermostat is just a temperature operated switch.

 

[Lone_viper]

Thanks... I actually have an electronic thermostat that I was going to connect, that has Yellow and Black wires for the 'switch'/solenoid , so I was thinking that black went to T being negative, and the Yellow to C, but given what you say above I am now not too sure?

 

[Lone_viper]

Doesn't matter, the thermostat is just a temperature operated switch.

Thanks... Conclusion I was coming to myself, but just wanted to make sure that I wasnt going to blow anything up

 

[Graham376]

Thanks... I actually have an electronic thermostat that I was going to connect, that has Yellow and Black wires for the 'switch'/solenoid , so I was thinking that black went to T being negative, and the Yellow to C, but given what you say above I am now not too sure?

I know nowt about electronic ones, mine is just simple mechanical one which doesn't need power feed.

 

[GHA]

Thanks... I actually have an electronic thermostat that I was going to connect, that has Yellow and Black wires for the 'switch'/solenoid , so I was thinking that black went to T being negative, and the Yellow to C, but given what you say above I am now not too sure?

you could put a meter across the black/yellow wires & see if/which has continuity to the neg power input, if one wire goes beep to neg then it will matter which way round, if not then *probably* not.
But the C terminals will be connected to battery neg. Just checked mine, home built thermostat which already has a ground connection, just noticed the thermostat C connection had come off but made no difference to it working as it has a ground, it's drawing current from T which turns it on/off.

 

[LadyInBed]

Leaving an led across + and D is useful for showing any fault codes if you have a problem.

 

[Lone_viper]

you could put a meter across the black/yellow wires & see if/which has continuity to the neg power input, if one wire goes beep to neg then it will matter which way round, if not then *probably* not.
But the C terminals will be connected to battery neg. Just checked mine, home built thermostat which already has a ground connection, just noticed the thermostat C connection had come off but made no difference to it working as it has a ground, it's drawing current from T which turns it on/off.

Great thanks....

So the Thermostat, its an XH-W3002 by the way for those that might want to have a play, has + and - as well as black and yellow which would go to the controller to 'switch' the compressor on.... Without anything turned on, there is continuity between the Black wires, which seems pretty obvious and not Yellow and Negative. But I also guess thats because the solenoid is its off position and therefore Open.
If I had the thermistor here I would power it up and see if that changed when it switched, but its on the boat run in to the fridge at the moment.... What a nightmare that was!