I was just putting beer in the ol’ fridge yesterday, and my Thermostar controller clicked off and started flashing. I hear it click every couple minutes or so, but it’s stopped adjusting temperature. I looked at the manual and a flashing light means “Compressor Safety Cycle”, but it doesn’t go into any kind of detail. I bypassed the controller just to get the fridge back down to temp, and then it kicked in again and seems to have worked fine overnight, but then as soon as I got up this morning (without opening the fridge), it started acting up again.
The problem is that it’s bad to keep turning the fridge/freezer off and back on again too quickly. The controller knows this, so once it turns the fridge off, the controller will refuse to turn back on before its internal timer says it has waited long enough. All good controllers have this feature, but use different names for it. Some let you set the short-cycle time, or even disable it, but it’s there to help.
The fridge was probably running just prior to you loading it up, so when you had the door open for loading the temperature went up but the controller thought it was too soon to run. Bypassing the controller to make the fridge run was the mistake. (Once or twice won’t screw up the fridge)
Now what it started up in the morning is something to look into. I’m not familiar with your controller, but you may need to tweak some settings.
I kept it on factory settings, which it recommended. I bypassed the fridge otherwise the temperature was rising pretty high. The controller has a setting on it that only takes temperature, as in it doesn’t control the fridge if it were to be plugged in, which is handy. So in bypassing the fridge and using that setting, I can set the temperature on the fridge itself (the little dial in the fridge) to keep it at temp. This way, the fridge doesn’t turn itself on and off all the time and works normally, and the controller can “take a break”.
It seems to be working, although the temperature range isn’t as accurate as with the controller, but it’s still holding around 5 degrees C, give or take 2 degrees. I’ll plug the controller in again soon and see how it goes.
Thanks for the rundown on how the controller cycles work! I’ll look into the settings a little more and maybe increase the on/off cycle (I know you can, I just haven’t tried it yet).
A couple more thoughts. It sounds like you’re using the controller to keep the fridge at our near the temperature the fridge wants to be at anyway. (If so, I’m not sure why you need a controller, but I’ll just accept that and move on.)
What you probably have then, is the two controllers fighting each other. When you use an external controller, the internal controller does not go away. if you want to use the external controller for tighter control; set the fridge to max cold, figure out how cold that gets, then set the external controller to something higher. I’m not sure how much higher you need to go though.
Finally, verify those factory settings. The default “Compressor Protection Delay Time” is only 2 minutes, meaning it should stay in protection mode for no more than 2 minutes. From your original post it sounded like it was staying in protection mode for much longer. If the setting is ACTUALLY 2 minutes, and it’s not coming out of protection mode, you may need to call support to find out why not. It could also be that hysteresis is set lower than the factory 2 degrees. If your fridge rises 2 degrees in less than 2 minutes, you should invest in a better insulated fridge.
