ARTC-SVX013A-EN
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• Thresholds
– Enable – On falling temperatures, as the ambient
temperature goes lower than the enable threshold,
free cooling is engaged.
– Disable – On rising temperatures, as the ambient
rises above the disable threshold, free cooling is
disabled.
• Fan/Valve Cross(X)Over (timer) and Differential
Temperature – At the extreme of free cooling where
there is more potential to cool the environment than
there is load on the system, the chiller changes from
modulating the fans to achieve setpoint to modulating
the valve.
– Fan control to valve control – Fans must be at
0percent and LWT must be lower than setpoint by
the differential for the length of the crossover timer.
– Valve to Fan Control – Valve must be at 100% and
the LWT must be greater than the setpoint by the
differential for the length of the crossover timer.
– This function provides a settable hysteresis to
prevent system cycling.
• Free Cooling button –
– Disabled - When disabled, the chiller does no free
cooling.
– Enabled – When enabled, the chiller does free
cooling.
Condenser and Evaporator Duty/Backup
Pumps
The chiller control system has two options for pumps
control as selected from the HMI configuration page – HMI
Pump Control.
• Disabled – No pump control from chiller control
system. This option must be selected when pumps are
not controlled by chiller control system. In that case,
BMS operates the pumps.
• MCX T3C Control – This pump control mode has been
deprecated but maintained in this document for
backwards compatibility.
• Arctic Cool Control – Requires T3C Companion
controller - this is the preferred control methodology.
This option must be selected to activate both
evaporator/condenser pumps control screens on
Devices menu.
Evaporator Pumps
To activate evaporator pumps functionality in the controller,
change Evap Pumps Control to display Enabled on the
HMI Configuration page. This also activates evaporator
pumps control screen.
Operating Procedures
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