Emerson Liebert iCOM Manual De Usuario

The Liebert iCOM control can adjust airflow manually through a BMS or dynamically using locally 

installed temperature sensors. Parameters related to VSD fan speed setting can be found in the 

Service Menu > Setpoints submenu on page 5 of 8. This menu allows the cooling unit's fan motor 

speed to be configured and adjusted for a variety of applications by selecting which sensor controls the 

fan speed. 
Four fan control modes are available: Manual, Supply, Return and Remote. All units ship from the 

factory with the temperature control and fan speed control sensor set to the Return Air Sensor.

• Manual Control: When set to Manual, the speed of the fan motor can be wrote using a hard 

wired analog input or remotely through an optional Liebert IntelliSlot

®

 card. Hard wired analog 

input signal types include 4-20mA, 0-10 VDC or 0-5VDC. See 6.0 - External Communication—

 for more information regarding Liebert 

iCOM intellislot monitoring options.
Before the building management system can control the fan speed, two parameters in the control 

must be set. S146 “Fan Control Sensor” must read Manual and line S164 “Allow BMS to change 

Fanspeed” must be changed to YES at the Liebert iCOM. Both parameters are found in Service 

Menus > Service Setpoints.

Fan speed may be written through the building management system to line S152. The user can 

change this locally. However, if the speed is set by the BMS, it will override the local setting.

• Supply, Return and Remote Control: These selections allow fan modulation using an 

equipped return, supply or remote sensor; see Table 4 for applicable control sensor combinations. 

If the fan control and the temperature control sensor have the same sensor selected, the control is 

considered coupled. If different sensors are selected, the control is considered decoupled. When 

operating the fan in coupled mode, the fan speed follows the call for cooling to reach the 

temperature setpoint. When the fans are operating in decoupled mode, the fans are ramped 

following the fan control band to achieve the fan setpoint.

S125 Fan

Control Sensor

Supply

Factory Default

(Coupled)

N/A

N/A

Remote Sensor

Recommended

(Decoupled)

 (Coupled)

N/A

Return

 (Decoupled)

 (Decoupled)

 (Coupled)