Emerson Liebert iCOM, Manual

Page: 117 / 172

Service Menu Parameters
109 Liebert
®
iCOM
®
for Liebert DSE
™
Figure 84 Setpoints screen, page 3 of 9
S124 Humidity Control Sensor —Defines which humidity value the humidity setpoint is compared
with. The return sensor is equipped with a Temp / Hum sensor and can calculate the dew point based
on iCOM's internal lookup table. If a sensor other than the return sensor is selected, then Liebert
iCOM will calculate the corresponding RH% based on that sensors actual temperature. The Range is
Remote or Return Sensor. The default setting is Return Sensor.
S125 Humidity Setpoint —Selects a humidity that the cooling unit will maintain by removing or
adding moisture to the air. The humidity setpoint will either be set in percent RH or as a Dew Point
Value depending on what the humidity control type is set for. This parameter is adjustable from 20-
80%. The default setting is 50%.
S126 Humidity Control Type —Selects the humidity control calculation. Setting this parameter to
“Relative” will control the humidity without considering any temperature deviations. “Predictive” and
“Absolute” control consider the temperature deviation from temperature setpoint so that a constant
level of moisture is kept in the area based on the humidity sensor reading and the temperature
deviation from setpoint. The default setting is “Predictive” (see 3.5 - Humidity Control ).
S127 Humidity Proportional Band —Adjusts the activation points of the humidifier and
compressors based on the actual sensor values deviation from setpoint. The smaller this number, the
faster the compressors and humidifier will increase capacity. Too small of a number may cause the
unit to short cycle or overshoot setpoint.
S128 Humidity Integration Time —Adjusts the capacity of the unit based on time away from
setpoint so that accurate humidity control can be maintained. If the integration time is set to 0, the
humidity control operates as a “proportional only” control. When an integration time is set, the
control mode changes to “PI” control.
S129 Humidity Deadband —Prevents overshooting of the setpoint and cycling between
humidification and dehumidification. The value entered in this field will be split in half by the
temperature setpoint.
S130 Dehum Temp Act/Set —Allows for a target temperature setpoint to be activated when a call
for dehumidification is enabled instead of the traditional method of overcooling the space by
increasing cooling to 100% and lowering fan speed if equipped. Must be in supply air control mode.
When a call for dehumidification is active, the supply or remote sensor setpoint will be lowered to this
parameter. This parameter should be set below the accepted dew point threshold of your space.
Used only when supply dehumidification is enabled.
S131 Dehum Setpoint Adjust/Filter —Sets the amount that the Dehum Temp Setpoint is adjusted
when the reheats activate. Example: If the unit is equipped with a reheat device, this parameter will
increase the dehumidification temperature as the call for reheats are increased until the reheat call is
at 100%. When the reheats are at 100%, the full Dehum Setpoint Adjustment will be applied.
NOTE
When the unit is in relative humidity control, only the right side of the menu is displayed and
dew point will display the left side of the menu.