Hypertherm Koolant Koolers N-Series, User Manual, Page: 29 / 77

Operation ‐ Shutdown
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7.2.1.4 Recirculation Pump Check
From the chiller controller home screen press and/or to highlight the MONITORING selection. Press
to access the MONITORING menu and press until the “Recirculation Circuit” monitoring screen
appears. Check the recirculation pump “Flow Rate” to make sure it exceeds 13.8gpm (52.2lpm) at 50Hz or
16.2gpm (61.3lpm) at 60Hz. If the recirculation pump flow rate is low, the flow rate can be increased by
opening the globe valve at the recirculation pump outlet.
7.2.1.5 Temperature Check
From the chiller controller home screen press and/or to highlight the MONITORING selection. Press
to access the Monitoring menu. The first screen will be the Process Temperature Monitoring screen.
Check the “Tout” on this screen. On initial startup the outlet temperature may be below the setpoint. To
increase the temperature quickly the chiller will turn on the tank heater to warm up the coolant. Within a
few minutes the outlet temperature should settle in close to the setpoint.
7.2.2 Remote Mode
Once the chiller temperature is in the desired range, the chiller is ready to be controlled remotely by the plasma
cutting system. To enable Remote Mode, turn the Local/Off/Remote Switch below the controller to the
position. There should now be a “Unit on in Remote Mode” message on the home screen. The chiller will now
be running in Standby Mode awaiting the Remote Start signal from the plasma cutting system. While in Standby
Mode the refrigeration system will not run, but the chiller will start the pumps and heater as needed to keep the
water warm.
NOTICE
While waiting for the Remote Start signal, the chiller water temperature may exceed the
setpoints if the ambient temperature is high. As soon as the chiller receives the Remote Start
signal, the refrigeration system will start and the water temperatures will drop to the
setpoints.
7.3 Shutdown
For normal shutdown, turn the Local/Off/Remote Switch below the controller to the “O” position. The chiller
controller will begin the normal shutdown sequence and display a “Shutdown in Progress” status message. The
normal shutdown sequence typically takes 2 ‐ 5 minutes. During this time the controller closes the liquid line
solenoid in the refrigeration system and pumps the refrigerant into the coil, so there is no risk of slugging liquid
refrigerant through the compressor on the next startup. It also turns off the tank heater while the recirculation
pump continues to run to dissipate any residual heat in the heater element. Once the shutdown sequence is
complete, the chiller controller will display a “UNIT OFF” status message.
CAUTION
Shutting off the chiller using the Main Disconnect Handle will bypass the normal shutdown
sequence and should only be used in emergency situations. Repeated shutdown using the
main disconnect handle will cause damage to the compressor system and void the chiller
warranty. It can also cause overheating of the inline heater and trip the heater limit switch.
Hypertherm, Inc. Part Number: 810540