The specific steps to turn on the refrigeration of a refrigerated compressed air dryer may vary depending on the make and model of the dryer, but here are some general steps you can follow:

Make sure the refrigerated compressed air dryer is properly installed and connected to the compressed air system.

Check that the power source is connected and the circuit breaker is turned on.

Locate the control panel of the dryer and turn on the power switch.

Set the temperature controller to the desired temperature for the refrigeration process.

Wait for the refrigeration system to start up and stabilize, which may take a few minutes depending on the size and type of the refrigerated compressed air dryer.

Monitor the operation of the dryer to ensure that it is functioning properly, and make any necessary adjustments to the temperature or other settings as needed.

If you have any doubts or concerns about how to turn on the refrigeration of your specific refrigerated compressed air dryer, it is recommended to consult the manufacturer's instructions or seek the assistance of a qualified technician.