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Old 09-02-2011, 03:12 PM   #161
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Default Rapid cycling compressor issue

For those who have tried this and find that their compressor is cycling too frequently:

These electromechanical thermostats have a built-in hysteresis (temperature above the set point at which the compressor will cycle on vs temperature below the set point where it will then turn off). The hysteresis is what prevents the compressor from rapid cycling, which causes premature failure. Unfortunately with these electromechanical thermostats the amount of hysteresis is related to the set point of the thermostat in such a way that as set point temperature is increased hysteresis is decreased. The exact amount is dependent upon the individual thermostat design and to a lesser extent unit-to-unit variability. Hysteresis can usually be adjusted by disassembling the thermostat and bending a leaf spring, but doing so is beyond the typical DIYer.

Thus my recommendation is if you are running into rapid cycling by trying this technique I suggest you return the factory thermostat to its original setting and invest in an external controller.

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Old 09-02-2011, 04:39 PM   #162
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Quote:
Originally Posted by AssistantBrewer View Post
For those who have tried this and find that their compressor is cycling too frequently:

These electromechanical thermostats have a built-in hysteresis (temperature above the set point at which the compressor will cycle on vs temperature below the set point where it will then turn off). The hysteresis is what prevents the compressor from rapid cycling, which causes premature failure. Unfortunately with these electromechanical thermostats the amount of hysteresis is related to the set point of the thermostat in such a way that as set point temperature is increased hysteresis is decreased. The exact amount is dependent upon the individual thermostat design and to a lesser extent unit-to-unit variability. Hysteresis can usually be adjusted by disassembling the thermostat and bending a leaf spring, but doing so is beyond the typical DIYer.

Thus my recommendation is if you are running into rapid cycling by trying this technique I suggest you return the factory thermostat to its original setting and invest in an external controller.

AssistantBrewer

What would you suggest in my case, where the compressor cycles pretty regularly to keep temps, but the relay (or other switch) keeps clicking on between compressor cycles?

Is this a result of the compressor trying to turn on and the relay preventing it based on a time limit for safe compressor cycles? If so, can this relay eventually wear out?
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Old 09-02-2011, 11:30 PM   #163
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I've been trying to get my freezer set up properly and am having a hard time even figuring out which direction I should be turning the dang screw. All the posts I've seen on screw direction say they are turning clockwise or to the right. Has anyone that's done this had to turn the screw counter clockwise?

Also, anyone done this with a frigidaire model, how did you turn the screw?

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Old 09-03-2011, 03:55 AM   #164
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Originally Posted by gsector
I've been trying to get my freezer set up properly and am having a hard time even figuring out which direction I should be turning the dang screw. All the posts I've seen on screw direction say they are turning clockwise or to the right. Has anyone that's done this had to turn the screw counter clockwise?

Also, anyone done this with a frigidaire model, how did you turn the screw?
I have a Frigidaire...I turned it about 8-10 cranks clockwise
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Old 09-03-2011, 01:58 PM   #165
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This worked like a dream on my Magic Chef. 12.5 turns in and im sitting at a balmy 38 degrees. Thanks for this walk-thru it saved me $60

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Old 09-03-2011, 04:12 PM   #166
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could the relays clicking have something to do with the frost free cycle on the newer units

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Old 09-03-2011, 05:05 PM   #167
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Quote:
Originally Posted by Agentaaron View Post
I have a Frigidaire...I turned it about 8-10 cranks clockwise
Thanks, I think I've got it now. I turned it too far counterclockwise and the spring came off, put it back on and the temperature is getting close.
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Old 09-09-2011, 01:13 PM   #168
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I was excited to find this thread a week or so ago as I'm currently building a keezer from the Frigidaire FFC0723GB. For the past week I have been trying to set the thermostat but I can't seem to get it right. The temperature swings too wildly.

I have a digital thermometer's probe sitting in a container of water in the freezer. There is also a case of bottled water, a corny of beer, and a CO2 tank in there to create some thermal intertia. I had the thermostat dialed in to where the compressor shut off at 39F. But the compressor never came back on and the internal temp got to 58F. So I backed the thermostat screw off just 1/8th of a turn to lower the setting a wee bit. The compressor came on and took the internal temp down to 30F. After it shut off, it rose to 36F and then the compressor came back on.

It seems to me that the internal thermostat in this model freezer is too finicky and has too wide of a thermal swing range (or whatever you call it) to be trusted. Unfortunately, I think I am going to have to put an external controller on the unit.

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Old 09-09-2011, 04:05 PM   #169
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That's exactly what I'm seeing. I can get it to hold steady at just barely above freezing, but any adjustment past that and it shoots up into the upper 50's. I just can't get it to sit around 40.

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Old 09-09-2011, 05:07 PM   #170
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Can anyone tell me which direction clockwise or cc raises the temperature setting on the frigidaire freezers?

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