Figure 86 Setpoints Screen - Emerson Liebert iCOM Manual

S141 Lockout FC at FC Fluid below—Prevents frost from building up on the free-cooling pipes
when the outdoor ambient is extremely low by turning Off the free-cooling circuit when the water
temperature is too low.
Figure 86 Setpoints screen, page 5 of 9
S146 Fan Control Sensor—Controls the fan speed for modulation. Options for this setting are
Supply, Return, Remote, and Manual Mode.
If manual mode is selected, then the fan speed can be controlled from the local display or through a
building management system.
S147 Fan Setpoint—Activated when a temperature sensor is being used to control the fan speed. If
the same sensor is used for temperature control and fan speed control, then this value will reflect the
same setpoint as the temperature control setpoint. Manual mode uses the Fan Speed STD for control.
S148 Fan Temp Control Type—Sets the type of control the unit will use to control fan speed.
PI controls gain is set in the Temp Prop / Integral parameter.
PI control will operate the fan speed so that the actual temperature of the fan control sensor is
equal to the fan temp setpoint. If proportional only is selected, the fan will change "ONLY" based
on the deviation from setpoint which will allow the actual temp to settle higher than setpoint.
S149 Fan Temp Prop/Integral—Adjusts the fan speeds rate of change based on the actual sensor
values deviation from setpoint. The smaller this number, the faster the fans will increase speed. Too
small of a number may cause the fans to increase decrease and overshoot setpoint.
Temperature Integration Time—Adjusts the fans of the unit based on time away from setpoint so
that accurate temperature control can be maintained. The proportional and integral work together
to maintain setpoint. Large P-Band with Small I-Time is typical to achieve a stable control.
S150 Fan Deadband—Avoids overshooting of the setpoint. The value entered in this field will be
split in half by the fan speed setpoint.
S151 Airflow Calibration—Allows the front display to be scaled to show the actual percentage of
airflow independent of the voltage operating the fan speed. This value cannot be set above the Analog
Output High Limit or below the Analog Low Limit for the fan set in the Advanced Menu. This also
includes the service menu fan speed parameters.
S152 Fanspeed Min/STD—Sets the range for the variable fans. Min sets the minimum speed that
the fan will operate at. Fan speed is modulated between the MIN and STD based on which sensor is
set to control, setpoint and the PI settings. If the controlling sensor is set to manual, then the STD
setting will control the current fan speed. This parameter is also adjustable through the BMS.
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Service Menu Parameters
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