Operation
Polycold Cryochiller
Single Circuit Modes of Operation
Installation and Operation Manual
Brooks Automation
6-6
214072 Revision B
After power up, when the compressor is turned on, the system always defaults to Standby mode.
On system Alarm/Fault which shuts down the compressor, once the compressor is turned back on, the
system defaults to Standby mode.
Standby mode can be selected using HMI or the command line interface.
If the unit is in a Standby mode, another mode (Cool or Defrost mode) can be selected.
Cool
When the unit is put into Cool, the Cool solenoid valve opens and the Defrost solenoid valve closes.
Cold refrigerant is pumped into the feed line then to the cryosurface and cools the cryosurface and
returns through the return line to the refrigeration unit. Inside the refrigeration unit, the refrigerant
releases the heat it absorbed from the cryosurface and then it is pumped through the system to repeat
the process.
Cool Mode Selection
Cool modes can be selected using the HMI or the remote command line interface or the web GUI to set
the default Cool mode for the Cool button(s).
The unit must first be turned to Standby or Defrost then back to the desired Cool mode.
Defrost
When the unit is put into Defrost, the Cool solenoid valve closes and the Defrost solenoid valve opens.
Hot refrigerant is pumped from the unit into the feed line then to the cryosurface where it warms the
cryosurface and returns through the return line. The unit automatically switches to Standby when the
return temperature or coil out temperature has reached the programmable set point temperature.
Some optional configurations of the Polycold Cryochiller include multiple Defrost Modes
Defrost Mode Selection
Defrost modes can be selected using the HMI or the remote command line interface to set the default
Defrost mode for the heat buttons.
Cool Mode
Description
Cool
(Standard)
Cool valve is open continuously until the unit is switched to Standby or Defrost. The cryo-
surface gets as cold as possible as fast as possible for the applied heat load.
Defrost Mode
Description
Standard Defrost
(standard)
Defrost valve is open until DEFR_SETPT is reached.
After DEFR_SETPT is reached, the valve is closed.
