Emerson Liebert iCOM Manual De Usuario

When the Liebert Air Economizer

™

 is not operating, the outside air damper is closed, the return air 

damper is open and the relief air vent fan is shut down. This permits air from the conditioned space to 

be drawn into the primary cooling unit, cooled and expelled into the conditioned space. The relief air 

vent is not required while the Liebert Air Economizer is not in service because no air volume is being 

brought into the conditioned space.

When a non-Liebert mixing box and damper motors are used, make sure that the following 

configurations are verified before a unit is placed into service.

• Verify that spring-closed return dampers are installed and operating properly. Without a spring 

return motor, the dampers will remain in the position they were in when power was present.

• While the Liebert Air Economizer is not operating, which could be due to the outdoor air 

conditions, a manual lockout through the Liebert iCOM or a Unit Off state will result in 2VDC 

(3.5VDC on 2-10V actuators) being present on the associated indoor and outdoor analog outputs. 

The 2VDC (3.5VDC on 2-10V actuators) signal must result in the outdoor damper being closed 

and return damper opened.

• During full Liebert Air Economizer operation, the Liebert iCOM will send 10VDC to the return 

and outdoor damper that must open the outdoor damper and close the return damper to its 

minimum position of 15%.

Risk of improper operation. Could cause frozen coils, resulting in degraded operation, water 

leaks, equipment damage and building damage.
Failure to verify that the indoor and outdoor damper operation is correct could freeze the 

chilled water coils, cause condensation within the data center or overload the main fan.

The Liebert Air Economizer control uses an outdoor temperature humidity sensor to detect when 

outdoor conditions are within the operating range. The outdoor sensor can be monitored from the 

Service/Economizer data menu on page 2 of 3 (see Figure 161).
The Liebert iCOM control is equipped with a series of setup parameters to allow adjustment and 

monitoring of the Liebert Air Economizer’s dampers and sensor. To access these parameters from the 

main unit screen:
1. Press the Down arrow key until User Menu is displayed.
2. From the User Menu screen, press the Right arrow key to enter the Service Menu.
3. Press the Enter key once in the Service Menu and use the arrows to navigate to the ECO icon on 

the bottom row.

4. Select this icon and press Enter.
The parameters for the Liebert Air Economizer are now viewable.
Parameters SA03 through SA06 of the Liebert Air Economizer screen are used to determine if outside 

air is eligible for use. Outside air requirements will vary slightly depending on if the Liebert Air 

Economizer is connected to a chilled water or direct expansion system. See Figure 38 for more 

information.