Fridge cooling period

Hi, I am aware there are constraints on the digital actuator to control the minimum off time and minimum on time of the fridge compressor.


And that there is a preset on the PWM block of 30m, I assume this would control the maximum time that the actuator is on.


I have just started a crash cool using a constant beer temp and have noticed that the fridge has been running for several hours. Should that be or have I missed a setting.

At 3am I changed it to a constant fridge setting to give the motor a breather.


With the decault settings, this can happen. 100% PWM output means the actuator is not turned off, and the mimimum off time does not kick in.

If you’re concerned about your fridge, you can add a “Max” constraint to the PWM, to prevent this scenario.

Personally, I have no idea whether it’s required for a compressor to have a down period.

A fridge has no problem with running constantly. The 30m period is the cycle time when it is not running 100%.

A compressor can overheat if it gets no rest after turning off. It needs time for the built up pressure to equalise before turning on again. The minimum off time is the most important constraint to protect the compressor.

Great, thanks for the reply, it’s not a new fridge I was just concerned about the extended running time.