Emerson Liebert DS Precision Cooling System 28-105kW User Manual

Humidity Ratio—Sets the minimum and maximum limits of outdoor air based on the amount of 

moisture content. The humidity ratio is set based on pounds of moisture per pound of dry air. This is 

equivalent to the dew point temperatures.
Wet Bulb Temperature—Read-only value that displays the outdoor wet bulb temperature. (This 

reading will be in metric values.)
Outdoor Temperature—Displays the actual outdoor temperature based on the Temperature 

Humidity sensor (Sensor C). When this parameter shows OK, the outdoor temperature requirements 

have been met to use economization. When NOK is shown, the outdoor temperature is outside the 

operating range set in the Liebert iCOM control.
Stop ECO at Setpoint + —Sets the temperature when the Liebert Air Economizer will be disabled 

due to an increasing outdoor air temperature. This parameter is added to the return air sensor 

setpoint and then compared to the outdoor temperature reading. If the outdoor temperature reading 

exceeds the return air temperature setpoint plus this parameter, the Liebert Air Economizer will be 

disabled. This is factory-set at 20°F (-6.7°C).
Economizer Mode—Displayed when the Liebert Air Economizer is available for use.
Dew Point Calculated—Displays the actual outdoor dewpoint based on the outdoor sensor.
Enable Economizer—Sets the Liebert Air Economizer operation to one of the following modes. 

These selections only determine if the Liebert Air Economizer is available for use they will not 

determine or override damper position. Damper position is always controlled by the sensor set to 

control temperature (i.e., Return / Supply Sensor).
Economizer Override—Sets the indoor temperature when the Liebert Air Economizer will be 

locked out. Even when all other parameters are satisfied, the Liebert Air Economizer will be locked 

out when the return air temperature sensor reads this value.
Delay After Fan Start—Sets the delay from the time the unit has been started until the 

ECO EMERGENCY OVERRIDE can be triggered.  This allows airflow to pass over the sensors to get 

an accurate reading before any emergency modes are activated.

Economizer (page 2 of 3)

to change parameter

to confirm

to select parameter

for next/previous unit
then 

UNIT   01

SA12
SA13
SA14
SA15
SA16
SA17
SA18
SA19
SA20
SA21
SA22

PASSWORD   (Actual Level  3)

????

Outdoor Air Sensor Temperature

79°F

Outdoor Air Sensor Humidity

33.0%

Outdoor Air Pressure

1013 .2hPa

Saturation Pressure WaterVapor

33.8hPa

Saturation Pressure Ice

42.8hPa

Partial Pressure  (Water Vapor )

11.1hPa

Volume Mixture Ratio (ppm/lol)

0.0ppm

Humidity Ratio (g/kg wet)

6.8g/k

Wet Bulb Temperature

59°F

and