Emerson Liebert iCOM Manual De Usuario

The Liebert Air Economizer can be configured to override SA04 through SA07 in the event the facility 

gets too hot. This override becomes active if the room temperature exceeds an adjustable high 

temperature high return temperature threshold set on line SA10. The emergency override will open 

the outdoor air damper and close the indoor air damper. The override function can be delayed after a 

fan start on line SA11, allowing airflow to pass over the room sensor to get an accurate reading before 

any emergency modes are activated. When the economizer is operating in emergency mode, an Eco 

Emergency Override event will be triggered. 

The restricted airflow switch inside the cooling unit must be adjusted for the Liebert Air Economizer 

to operate properly and efficiently. To adjust the switch:
1. Inspect all connections, restore power to operate the unit’s blower.
2. Go to the Service Menus, Diagnostic / Service Mode. 
3. Enter the Service Menu password 5010.
4. Enable manual mode on line S313. The unit will shut Off.
5. Go to line S314 Motors and change the value displayed from No to Yes. This will allow the 

evaporator fan to run with the outside air damper at minimum position.

6. Confirm the fan is running at minimum speed. This is shown on line S343 “Analog Out 3” of the 

Diagnostics / Service Mode.

7. Confirm the outside air damper has moved to the minimum position by visually checking damper 

position.

8. Find the restricted airflow switch in the cooling unit (Figure 35 shows the switch location in both 

the Liebert CW

™

 and Liebert DS

™

).

9. Turn the restricted airflow switch alarm setpoint knob clockwise until it trips. The cooling unit 

will also alarm.
a. Place a voltmeter on Terminal 56 and on the chassis ground.
b. Turn the airflow sensor counterclockwise until the voltmeter indicates 0VAC.
c. Turn the airflow sensor adjustment screw clockwise until the voltmeter indicates 24VAC.
d. When the voltmeter shows 24VAC, turn the screw counterclockwise one full turn.

Once the airflow switch has been calibrated, go to the Service Menus, Diagnostics / Service Mode. 

Using the Service Menus password 5010, disable manual mode on line S313.
Cycle power Off to the unit using the I/O button, then turn the unit Off at the disconnect. Cycle power 

back On to the disconnect, then press the I/O button once the control has finished booting up. Verify 

unit operation as the fan starts and outside damper opens.  If a 'Reduced Eco Airflow' alarm occurs 

during when the unit starts, the alarm time delay located in Service, Set Alarms may need to be 

adjusted higher. 
The reduced airflow alarm is latched in the control for 90 minutes after calibration. Acknowledge this 

alarm and allow it to clear by pressing the horn button on the control once. The alarm may also be 

cleared by shutting Off power to the Liebert iCOM and cycling power to the cooling unit. The unit will 

now resume normal operation.

If the room air temperature becomes too cold, the control will call for heating. Heating mode is 

controlled by the Temperature Proportional Band, explained in 3.3 - Temperature Control.