Liebert iCOM
®
Control
107
Liebert
®
CRV
™
S119 Dehum Integration Time
—Adjusts the capacity of the unit based on time away from setpoint
(0 - 25 minutes) so that accurate humidity control can be maintained. This parameter is active only
when the control type is set to “PI.”
S120 Dehum/Heat Low Limit 1
—Sets the temperature at which the compressor will be deactivated
for dehumidification control.
Example: If Low Limit 1 is set to 4°F (2.2°C) and the temperature setpoint
is 70°F (21.1°C), then dehumidification will turn Off at 66°F (18.8°C).
S121 Low Limit 1 Reset
—The Low Limit is reset - when set to 2.0K, dehum will be allowed to
restart at 20.8°C (18.8 + 2, using the example in the manual). This parameter controls when the
temperature has increased enough to re-enable dehumidification.
Figure 83 Service menus
—
Setpoints parameters screen - Page 3
S124 Fan Control Type
—Sets how the fan speed will be controlled. Setting this parameter to Auto
mode=0 will allow the Liebert CRV to drive the fan based on the temperature sensor selected for
sensor control type. Setting this parameter to Manual mode=1 allows the Liebert CRV to be set to a
fixed fan speed either through the local display or through a building management system.
S125 Fan Control Sensor
—Selects which sensor will drive the Liebert CRV fans when set to Auto
mode for the fan control type
[0 = Supply Sensor, 1 = Remote Sensor or 2 = Return Sensor]
.
S126 Fan Regulation Type
—Sets the fans’ control type. It can be set to
0 = Proportional
control,
which will modulate the fans linearly based on the deviation from the setpoint. Also it can set to
1=Proportional integral
control, which is also available and works in the same manner as the
temperature control integral term.
S127 Fan Delta
—Sets the fanspeed setpoint. The delta accounts for the temperature rise from the
Supply Air Sensor and the Remote Rack sensors by adding the Fan Delta to the Temperature
Setpoint (S102). This eliminates the possibility of setting the remote rack temperature setpoint lower
than the supply temperature setpoint.
S128 Fan Speed Proportional Band
—Adjusts the fans rate of change based on the actual sensor
values deviation from setpoint or the delta. The smaller this number the faster the fan will increase
its speed. Too small of a number may cause the fans to excessively reposition.
Note that the Fanspeed Speed Proportional Band parameter can be set to Auto and decoupled.
S129 Fan Speed Integration
—Adjusts the fanspeed of the unit based on time away from setpoint.
The setting is applied only to decoupled modes (refer to
).
S130 Fan Speed Manual Setpoint
—Sets the speed of the fans when the unit is placed into Manual
Fan Speed Control mode [0-100%].
S131 Fan Speed STD
—Sets the maximum fan speed of the unit under normal operating
circumstances (0-100%).
S132 Fan Speed Min
—Sets the lowest fan speed operation of the unit [0-100%].
S133 Fan Speed Dehum
—Sets the fan speed the unit will operate at during a call for
dehumidification (0-100%). The fan speed will position to the highest requirement. If the call for fan
speed from the remote rack sensor is requesting more air volume than the Dehum fan speed, then the
fans will run at the remote sensor’s fan speed request.
NOTE
The fanspeed settings S126 to S129 apply only to decoupled modes. When coupled, all values
disappear and have no effect.