Help with keezer temp control

[canihaveurpants]

Finished my keezer build last week and have installed a Johnson A419 to keep my kegs cool. My issue is that it seems to take forever to cool the kegs down when a cycle runs but they heat back up really quickly. I have the controller set for 43 degrees (Diff of 2 and ASD of 12). The keezer will bring the kegs down to 41 (after running for quite a while) but then just 15 minutes or so later the motor will be running again as the temp has risen to 43. My probe is covered with some paper towel and then duct taped to one of my kegs. Any ideas? Don't want to kill this compressor!

 

[freisste]

Not totally sure I understand the issue, so if I'm out in left field, ignore me...

Maybe you are only cooling the outside of the kegs by the time the compressor kicks off. Then as soon as they are not being actively cooled, the beer inside them warms them up, causing the compressor to kick back on.

How long have you left them in the keezer to cool? It may just be how it runs during the initial cool down, after which it runs more normally.

Not sure if my description makes sense or not...

 

[canihaveurpants]

My issue is that the compressor is running much too often and I don't really understand the reason why. The keg my probe is adhered to has a full 5 gallons so the thermal mass of it should be quite large. I can't grasp how 5 gallons of beer would heat up 3 degrees in less than 15 minutes (from 41 to 43). It should take much longer than that I would think. Maybe the probe attached to the outside of the keg wall isn't my best option. I saw it suggested multiple times on these forums but maybe I will try dangling the probe freely within the cooler and see how that works out.