Emerson Liebert iCOM - Manual (Page 32)

Operation
26
Standard Mode
In Standard mode, the SCR reheat operates only when the Temperature Proportional Band calls for
heating. SCR reheat output is adjusted proportionally as the Temperature Proportional Band varies
the requirement for heating from 0% to -100%. Compressors operate only when there is a call for cool-
ing as described in 3.3.2 - Compressor Control.
Figure 21 illustrates how SCR reheat operates when SCR Control Type is set to Standard mode.
Figure 21 Two single-step compressors with SCR reheat set to Standard mode
Temp Setpoint : 70°F
Proportional Band : 8°F
Deadband : 0°F
Cool 2
On Cool 1
On
Cool 2
Off
Cool 1 Off
SCR Off
SCR
On
0% 100 %
Cooling
-100%
Heating
74 71 72 73 66 67 68 69 70
½ Proportional Band
Cooling 1 On
Cooling 2 On
½ Proportional Band
SCR On