Any refrigeration engineers or anyone competent with fridges?

[S.E]

Are there any refrigeration engineers or anyone competent with fridge repairs that can advise me on this?

Our five year old fridge freezer stopped working last week so we bought a replacement in the January sale rather than have it repaired.

The old fridge freezer is large enough for a 60L fermenter and in great condition apart from the fact that it keeps stopping and the temperature lights start flashing so I want to get it running and use it as a fermenting fridge.

I have a wiring diagram for it and by unplugging the power module socket from the PCB and connecting the compressor, compressor cooling fan and the inside freezer fan directly to the main switch I have managed to get it running continuously without stopping now so intend to plug the fridge in to an STC1000 to control it.

I have also disconnected all the sensors and frost free heaters and removed the flap thermostat/motor unit from the fridge so the cold air from the freezer now blows down to the fridge unrestricted.

It seems to be working exactly as I want it now but I haven’t dared to leave it running unattended yet so my question is, is there anything else I ought to do or reconnect for it to run safely?

Thanks

View attachment Fridge 1.pdf

View attachment Fridge 2.pdf

 

[Ducatiboy stu]

Looking at it you need the fans running with the compressor. Couldnt see where the thermostate is but if you wired the comp and fans thru the stc it should work fine. You may have an issue with moisture build up as it will no longer be using the defrost cycle.

 

[S.E]

I think the compressor fan is wired to the compressor according to the diagram but I haven’t been able to find the fan itself, is it built in to the compressor?

I have another old fridge and there is a fan beside it but on this one and my new fridge I can’t see the compressor fan.

I did also wonder about moisture build up and it frosting up without the heaters but do you think it would matter?

Cheers

 

[Ducatiboy stu]

Possibly. All the control cct does is work out when to defrost and fires up the heaters. You could stuff around and put a manual switch in or just leave it where a little trickle of water wont hurt.

 

[S.E]

Possibly. All the control cct does is work out when to defrost and fires up the heaters. You could stuff around and put a manual switch in or just leave it where a little trickle of water wont hurt.

I think the water trickles down a pipe to a tray on top of the compressor to help cool the compressor by the look of it, but Ill probably be putting it somewhere a little water won’t hurt.

From tests so far I don’t think In need to put the heaters back in as the freezer doesn’t freeze now just stays more or less the same temp as the fridge. (Well it freezes when the unit is first plugged in but soon stabilises as the fridge cools)

Cheers

 

[Ducatiboy stu]

Interesting....a fridge of that age should draw cold air from the freezer and feed it into the fridge. You should have a fan somewhere behind the freezer, you may need to pull the internal back out of it to find it. Makes sure its working because if it isnt then it wont freeze and cool properly. I had mine ice up and it wouldnt freeze or cool.

 

[TidalPete]

I am very far from being competent with electrics but if you're using/planning to use an STC-1000 or similar wouldn't you be able to get rid of any moisture remaining in your fermenting fridge by adding a heating source after winding up the existing fridge thermostat to the max?
As for the fan that you say is connected to the compressor???? Wouldn't it work anyway if you merely changed thermostats from fridge to STC-1000/or similar??

Have never set up an STC-1000 in my life but just going by experience with TempMates which are pretty similar.

Any comments appreciated from you Stu or from anybody else.
All part of the learning curve.

 

[brocky_555]

Where are you ? I might be able to give you a hand if you are close ( for a nominal fee, beer economy and all that ) Licensed leco and all that.

 

[S.E]

Where are you ? I might be able to give you a hand if you are close ( for a nominal fee, beer economy and all that ) Licensed leco and all that.

I’m in the Illawarra so a bit far from you. Thanks anyway.

 

[S.E]

Interesting....a fridge of that age should draw cold air from the freezer and feed it into the fridge. You should have a fan somewhere behind the freezer, you may need to pull the internal back out of it to find it. Makes sure its working because if it isnt then it wont freeze and cool properly. I had mine ice up and it wouldnt freeze or cool.

Yes it draws cold air from the freezer and the freezer fan works fine. The fan now blows the cold air from the freezer continuously through a big hole between the freezer and fridge because I have removed the flap thermostat that was previously in the hole and controlled the fridge temp. So in effect the fridge compartment is now a freezer as well but I can control the temp with an STC1000.

I couldn’t find what was wrong with the appliance (though I suspect it was the control board) so I have disconnected everything, bypassed the control board and connected the live from the main switch button directly to the compressor (also the compressor fan I think?) and freezer fan.

The appliance is now running exactly as I wanted but I’m not sure if there is something else I should reconnect for it to run safely as I only have a basic understanding of how they work.

What is on my mind I suppose is have I bypassed an important safety cut out that I’m not aware of or can I just rely on the STC1000 control it?

If the STC1000 develops a fault and does not stop the fridge running what is likely to happen?

Will it keep running until the appliance freezes up and stops running?

Or will it keep running until the appliance freezes up and explodes?

 

[S.E]

I am very far from being competent with electrics but if you're using/planning to use an STC-1000 or similar wouldn't you be able to get rid of any moisture remaining in your fermenting fridge by adding a heating source after winding up the existing fridge thermostat to the max?
As for the fan that you say is connected to the compressor???? Wouldn't it work anyway if you merely changed thermostats from fridge to STC-1000/or similar??

Have never set up an STC-1000 in my life but just going by experience with TempMates which are pretty similar.

Any comments appreciated from you Stu or from anybody else.
All part of the learning curve.

I have ripped out the original thermostat and sensors. I have also disconnected the heaters. Moisture build up isn’t causing any problem at the moment but that may change when I start fermenting in it.

Cheers

 

[Ducatiboy stu]

How cold is it getting now.

If it hasnt gone bang by now it should be fine. If you wire the STC in line with the "live" wire it wil work fine. Disconnect the heaters as they only run when the compressor stops in it de-frost. Otherwise it will use more power and make the compressor work longer.

 

[S.E]

How cold is it getting now.

If it hasnt gone bang by now it should be fine. If you wire the STC in line with the "live" wire it wil work fine. Disconnect the heaters as they only run when the compressor stops in it de-frost. Otherwise it will use more power and make the compressor work longer.

[SIZE=12pt]The fridge dropped to about 6C before I unplugged it. The freezer initially dropped below freezing but went up to about 10C soon after it was unplugged.[/SIZE]

[SIZE=12pt]I kept plugging it in and out for a couple hours to keep the fridge temp around 18C and the freezer hovered around 14C[/SIZE]

[SIZE=12pt]The heaters are disconnected. I haven’t got around running it through the STC yet, Ill go and do that now.[/SIZE]

[SIZE=12pt]Cheers [/SIZE]
[SIZE=12pt]Sean [/SIZE]

 

[S.E]

All seems to be working fine. I have been fermenting an ale @18c in the fridge since Monday the freezer stays around cellar temps so I can use it to store and serve cube/casks of ale.

I may see if I can attach my hand pump just above the freezer compartment somehow and pump directly from it. It may be a little high though.

Cheers Sean

 

[DJ_L3ThAL]

Probably not fermenting ales due to the fridge not running that often, but if you want to do lager temperatures I'd say you will eventually freeze up the suction line and the compressor will have to run awfully hard to the point that the evaporator coils will also freeze and if the fan blows over them the ice build up and block the fan.

I know this from experience with my kegerator that had a faulty defrost time. I was opening the door even 2-3 days to get a beer (more often on weekends etc) and after 1-2 weeks, middle of the night you'd hear the scratching of the fan on the ice that had built up. Replacing the defrost timer fixed it and now the fridge runs perfectly and maintains it's temperatures.

So basically, you need the defrost function for it to avoid freezing up, although if you minimise (completely) opening the doors until fermentation is over and then give it 24 hours to defrost naturally (having the fridge turned off), you should have yourself a functional fermentation fridge

 

[S.E]

Probably not fermenting ales due to the fridge not running that often, but if you want to do lager temperatures I'd say you will eventually freeze up the suction line and the compressor will have to run awfully hard to the point that the evaporator coils will also freeze and if the fan blows over them the ice build up and block the fan.

I know this from experience with my kegerator that had a faulty defrost time. I was opening the door even 2-3 days to get a beer (more often on weekends etc) and after 1-2 weeks, middle of the night you'd hear the scratching of the fan on the ice that had built up. Replacing the defrost timer fixed it and now the fridge runs perfectly and maintains it's temperatures.

So basically, you need the defrost function for it to avoid freezing up, although if you minimise (completely) opening the doors until fermentation is over and then give it 24 hours to defrost naturally (having the fridge turned off), you should have yourself a functional fermentation fridge

I haven’t fermented a lager since I was about 14 so shouldn’t be a problem for me.

Ive also blocked the air holes to the freezer so the cold air blows directly to the fridge. The freezer still gets colder than the fridge though but very little.

Cheers