Liebert iCOM Microprocessor TM-10098 - Manual (Page 17)

iCOM
Controls Training and Service Manual
The example below is based on a temperature set point of 70
°F with a control
band length of 4
°F, which is ½ of the programmed temperature proportional band
value.
STAGE TEMPERATURE
Cool 1 ON Set point plus 1
°F
Cool 2 ON Set point plus 2
°F
Cool 3 ON Set point plus 3
°F
Cool 4 ON Set point plus 4
°F
Cool 4 OFF Set point plus 3
°F
Cool 3 OFF Set point plus 2
°F
Cool 2 OFF Set point plus 1
°F
Cool 1 OFF Set point
4 Stage Compressorized Cooling – With Dead Band
Temp Set Point: 70
°F
Proportional Band: 8
°F
Dead Band: 2
°F
70 71 72 73 74 75
Increasing Temperature
Cool 2 On
Cool 1 Off
Cool 4 On
Cool 3 Off
Temp Set Point + (1/2 Dead Band + 1/2 Proportional Band)
DB
Cool 1 On Cool 3 On
Cool 4 Off
Cool 2 Off
Note: in the above example that the control band begins at the 70
°F temperature
set point and has a length of 5
°F, which is ½ of the programmed temperature dead
band value plus ½ of the programmed temperature proportional band value.
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