Emerson Liebert iCOM Manual De Usuario

Temperature Deadband
The deadband range is used to widen the setpoint and prevents small temperature changes from 

activating compressors and valves. When the air temperature falls within the deadband, the control 

operates the same as if the temperature equaled the setpoint exactly. This setting helps maximize 

component life by preventing excessive component cycling. Figure 25 illustrates how the 

temperature proportional band and deadband is evenly divided on either side of the temperature 

setpoint.
The parameter AutoSet Enable, found in Service Menu, Setpoints, automatically sets the 

proportional bands for temperature and humidity, and both the integration time factors according to 

the type of unit (chilled water, single or dual compressor)

.

Depending on its type, a Liebert cooling unit may have one or two compressors with or without 

unloaders or variable capacity.

One Single-Step Compressor Without Unloaders—One-Step
One single-step compressor, Cool 1, is started at 100% call for cooling from the temperature 

proportional band and stopped at 0% (see Figure 26).

Two Single-Step Compressors Without Unloaders—Two-Step
First single-step compressor, Cool 1, is started at 50% calculated output from the temperature 

proportional band, and stopped at 0%. The second compressor, Cool 2, starts at 100% and stops at 

50% (see Figure 27).
One Compressor With an Unloader—Two-Step
The two-step compressor is started unloaded at 50%, Cool 1, calculated output from the temperature 

proportional band and stopped at 0%. At 100% the compressor starts fully loaded, Cool 2, and returns 

to unload operation at 50% (see Figure 27).