The Startup and Freeze Protection Program

iCOM Control Training and Service Manual

The Startup and Freeze Protection Program

The sequence for the call for cooling with the program features is as follows:

The need for cooling is defined by the control setting for the temperature setpoint, proportional band, and deadband (if used). At this point the Winter Start Kit (WSK) time delay is the wait period for the compressor to run without the indication of the low-pressure condition (also known as LP bypass). The WSK time delay is programmable with a range of 0 - 5 minutes. If the LP switch setting is achieved in this time then full cooling is in process with the Freeze Protection (FP) now watching the LP for an additional 10 minutes (fixed). If the LP remains closed the cooling process continues.

If the WSK is not made in the set time period the cooling process stops and waits an additional 5 minutes with the compressor off (no pumpdown). The liquid line solenoid valve will remain open during this time period. If the LP switch is made the control will now advance and wait for the freeze protection time delay as stated as above. If the LP switch does not prove in the WSK time delay period plus the 5 minute wait period, the compressor is locked off and the Low Suction Pressure Alarm will activate. A power off/ on reset is required to reset the cooling function.

If the WSK is made and the control is in the 10 minute Freeze Protection (FP) wait time period and this function does not prove the LP the control will go into additional 10 minute wait (fixed), with the compressor off (no pumpdown) and the liquid line solenoid valve to remain open. If the freeze protection does not make

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Liebert TM-10098 service manual The Startup and Freeze Protection Program, iCOM Control Training and Service Manual