Bypass thermostat HELP!

[carterson1027]

So I recently bought a danbydkc644 used for cheap. I have have read a lot online about how the tower is warm and how the thermostat is not great. Im going to put a blower in to the tower and also want to bypass the thermostat and use a JohnsonA419 temp controller. I just don't know where and what wires I should cut/put together to bypass the thermostat. Does anyone know? Thanks

 

[carterson1027]

This is the wiring set up. I'm not sure how to make this bypass. Can anyone help l? PLEASE

 

[day_trippr]

and



Two ways to do this, one easier than the other.

o You wire up your A419 with its own line cord going into it and an outlet going out, plug the fridge line cord into the switched outlet, then remove the Red wire from the controller that goes to the compressor via the overload protector and connect that wire directly to the Black wire feeding the same controller.

With that done you'll control the whole fridge from the A419 via the line cord though it means the display will be pretty much useless.

o Incrementally harder, wire up the A419 input the same way, but remove the same Red wire from the fridge controller, and connect that directly to the A419 relay. That leaves the fridge display functional. You could use a line cord with the Red as Line and grab Neutral and Safety Ground connections for it from the existing wiring.

- In any case, you'll need to connect a 120VAC Line wire to the TB1 "120" contact as shown (this supplies power to the control logic) then daisy-chain the same wire to the "C" contact on TB2 (this supplies power to the output relay Common contact) shown as "RED 1" in the graphic.

- Connect the 120VAC Neutral supply to TB1 AC COM contact.

- Disconnect the red wire from the Control Module that goes to the Overload Protector and Compressor.

- Connect that red wire to the A419 TB2 NO contact ("normally open") shown as "RED 2" in the graphic.

- Wire the sensor to TB3 as shown and run it inside the fridge.

- Make sure the A419 jumpers are set for "Cooling/Cut-out:



- Program the A419 and you should be off and running.


Cheers!

 

[carterson1027]

Wow this is great info. I'm going to plug the refrigerator directly into temp control and not hard wire it. I'm going to take a look in the morning. Hopefully I can figure it out. I'll keep you posted. Thanks!

 

[day_trippr]

Aaand your aborted post to the other thread caused me to recheck your wiring diagram and you have the same gotcha: that fridge uses a 12V DC evaporator fan, and if you bypass the oem thermostat the fan won't run when your controller runs the compressor.

As I advised in the other thread, the easiest work around is wire a 12V DC wall wart so it gets AC power from the same circuit that runs the compressor, then use the wall wart output to run the evap fan...

Cheers!

 

[carterson1027]

Aaand your aborted post to the other thread caused me to recheck your wiring diagram and you have the same gotcha: that fridge uses a 12V DC evaporator fan, and if you bypass the oem thermostat the fan won't run when your controller runs the compressor.

As I advised in the other thread, the easiest work around is wire a 12V DC wall wart so it gets AC power from the same circuit that runs the compressor, then use the wall wart output to run the evap fan...

Cheers!

Thanks that's great information. I aborted the other post because I saw this one seconds after.
Can't wait to work on this in the morning

 

[carterson1027]

I made the bypass and it worked great! I plugged it in and let it run for a bit and the Evap fan that's in there actually still goes on. It's weak but it was before as well. I monitored the temp with a thermoater I have running in to the box and the temp dropped no problem and then I unplugged it. I don't have the temp controller yet because I didn't want to order until I was sure I can make the bypass. my friend has an inkbird controller he's not using so I may try that out. I'm going to cool the tower with a blower that will run off a switch so I don't have to have it on all the time( sometimes I let my body dry out for a few days) . This should create some air circulation. Should I still had another fan that goes on/ off with compressor ? Im guessing what you were telling me is to have the temp controller power on the compressor AND the fan. So get a plug that goes into temp controller that splits with two more plugs , one for compressor and 1 for fan ?

 

[day_trippr]

Should I still had another fan that goes on/ off with compressor ? Im guessing what you were telling me is to have the temp controller power on the compressor AND the fan. So get a plug that goes into temp controller that splits with two more plugs , one for compressor and 1 for fan ?

The evaporator fan has to run whenever the compressor runs. Yours likely turned on because the oem thermostat is still "working", saw the temperature didn't match its setting, and "turned on" the compressor and evap fan.

Problem is if you're fermenting the temperature will likely always be warm enough for the oem thermostat to think it needs to cool, so the evap fan will run pretty much all the time. Aside from wear-out that's not a huge problem, but if you wanted to fix that, use the wall wart solution.

You can wire your A419 relay to switch both sockets in a duplex outlet and plug the fridge into one and the wall wart into the other...

Cheers!