Cornelius "Pepsi" cooler power?

[ibrubeer]

I recently purchased a used Cornelius "Pepsi" style cooler, with the 2 sliding glass doors on the front. It is one of the big 7 foot tall units with all of the refrigerant motors and such on the top. The cooler sits in my basement in a temperature controlled room.

My question concerns power to the cooler. I would like to use an external temperature controller (Johnson Controls) with it. It has a temp probe that goes into the cooler and basicly shuts off power when you get to the temperature that you want, and turns it back on when you get to the temperature offset. It turns power on/off to the whole cooler. Will this type of setup shorten the life of the cooler/compressor?

I don't aim for super cool temperatures. It would normally be set for around 40F. I wouldn't open the doors very frequently to let the cool air out. Hopefully it would cool to the desired temperature, and hold it for a while before needing to cool again. It is destined to be a beer kegerator.

What do you think?

[chillin out]

I don't see a problem with what you are trying to do.

Replacing the original stat with another kind will not do any damage unless you are trying to keep a very close control over the temp which will make the comp short cycle and burn out.
Keep the differential high on the external stat.

Chillin:):)

[ibrubeer]

I just wanted to double check. The cooler seemed to run all of the time, but that was just a fan that apparently circulates the air inside the cooler. The condenser wasn't running all the time. I think it will be OK too. This is just my first big Cornelius cooler like that, and I didn't know if it had any general quirks.

Thanks!

[taz24]

I just wanted to double check. The cooler seemed to run all of the time, but that was just a fan that apparently circulates the air inside the cooler. The condenser wasn't running all the time. I think it will be OK too. This is just my first big Cornelius cooler like that, and I didn't know if it had any general quirks.

Thanks!

Why do you want to turn the whole fridge off?
Why not replace the old thermostat with the new controler and then let the thing run as it should?

Is it because of power consumption (to keep the cost down)?

The evap fans are designed to run to circulate the air inside the box, if you turn the whole fridge off the fans will stop circulating the air. The fridge will warm up and when the thing cuts in again it will have more work to do, to even the temp inside the fridge again.

Also you need to look at the controler to check it can take the power of the start up of the whole fridge time after time after time. Starting the whole fridge will require a larger relay than just starting the comp and cond fan.

Cheers taz.

[ibrubeer]

Why do you want to turn the whole fridge off?
Why not replace the old thermostat with the new controller and then let the thing run as it should?

Is it because of power consumption (to keep the cost down)?

The evap fans are designed to run to circulate the air inside the box, if you turn the whole fridge off the fans will stop circulating the air. The fridge will warm up and when the thing cuts in again it will have more work to do, to even the temp inside the fridge again.

Also you need to look at the controler to check it can take the power of the start up of the whole fridge time after time after time. Starting the whole fridge will require a larger relay than just starting the comp and cond fan.

Cheers taz.

Yes. It is just a beer cooler that isn't opened that much. I didn't want to pay to run the fans the whole time, nor add wear to the fans if the doors are rarely opened.

I am using a Johnson A419 external controller with a temp probe laying inside the fridge. I have it set to 42F with a 3F differential. It takes a while for it to warm back up to 42F from 39F. I guess I thought it unnecessary to run the fans inside circulating the air all the time. There isn't that much stuff inside that I was worried about "warm" spots.

In regards to checking that the controller can handle the startup of the cooler over time, can you give me a little more information as to how I determine this? Johnson's manual for the controller says that it can be used to run "retail store display freezers and reach-in coolers." I would think my cooler would fit into this category, but would like to be sure....

Thanks!

[chillin out]

Johnson's manual for the controller says that it can be used to run "retail store display freezers and reach-in coolers." I would think my cooler would fit into this category, but would like to be sure....
That is only an example of a used application. In these instances the stat would only control a solinoid valve and nothing else.
You want it to control a compressor and 2 fans.
You need to find out the proper data on this stat, or make it control a relay instead.

Chillin:):)

[taz24]

Yes. It is just a beer cooler that isn't opened that much. I didn't want to pay to run the fans the whole time, nor add wear to the fans if the doors are rarely opened.

I am using a Johnson A419 external controller with a temp probe laying inside the fridge. I have it set to 42F with a 3F differential. It takes a while for it to warm back up to 42F from 39F. I guess I thought it unnecessary to run the fans inside circulating the air all the time. There isn't that much stuff inside that I was worried about "warm" spots.

In regards to checking that the controller can handle the startup of the cooler over time, can you give me a little more information as to how I determine this? Johnson's manual for the controller says that it can be used to run "retail store display freezers and reach-in coolers." I would think my cooler would fit into this category, but would like to be sure....

Thanks!


I would set the differation to about 5 deg to give that little extra time off,take the temp down a little lower and let it warm up a little higher.
Is the thing run from a domestic plug? In the UK the maximum that can be run on a domestic plug is 13amp so if your controler is rated at 16 amp or above it will handle the start ups.

taz.

[cleanNcold]

I see a potential problem or two with using the tstat like this. First, there is another reason other than air circulation for the evaporator fan(s). They defrost the evaporator while the compressor is off. Over time, you will freeze the evaporator and the compressor will run continuously freezing it even more. Dont mess with years of engineering. The other problem could be the location of the sensing bulb. If not properly located, it too may cause the evaporator to freeze.

[1mikeefc1]

completely agree with cleanncold. If evap fans are disabled when off on temperature then it wont be defrosting on off cycle as is designed, this will then cause evap icing up and liquid refrigerant getting back to compressor. This could open a whole can of worms and could be costly.

[ibrubeer]

That is only an example of a used application. In these instances the stat would only control a solinoid valve and nothing else.
You want it to control a compressor and 2 fans.
You need to find out the proper data on this stat, or make it control a relay instead.

Chillin:):)

Ok. I hate to ask a silly question. But what exactly am I looking for? What specification on the Controller am I concerned with? Amperage? The manual says for "Full Load Amps" it can handle 16A. It has a regular 120V plug. Aside from the cooling fan question, is this what I am concerned with for the Controller being able to handle the load on the cooler?

[ibrubeer]

I see a potential problem or two with using the tstat like this. First, there is another reason other than air circulation for the evaporator fan(s). They defrost the evaporator while the compressor is off. Over time, you will freeze the evaporator and the compressor will run continuously freezing it even more. Dont mess with years of engineering. The other problem could be the location of the sensing bulb. If not properly located, it too may cause the evaporator to freeze.

I think I see where this is heading, unfortunately. My thinking was that this is a cooler that is seldom opened, so once it is cooled off to the target temperature, it should stay there for a while. It is unnecessary wear and tear (and noise and electricity) to run it in the meantime. I certainly don't want to create a situation where I damage components or shorten the life of the cooler though.

Is the consensus that I should just plug it in and let the circulation fans run all the time? That if I plug the cooler into an external controller that interrupts power when reaching the desired temperature, this will shorten the life of the cooler, and has the potential to create an expensive problem?

The temperature sensor for the controller (sensing bulb?) is currently laying on a shelf near the floor of the cooler. It is the probe for the Johnson controller.

Thanks for all of the input!