Red Lion TSC - Manual (Page 42)

Heat-Cool Overlap/Deadband (db-2)
This parameter defines the area in which both heating and cooling are active
(negative value) or the deadband area between the bands (positive value). The
parameter units are degrees or tenth’s of degrees (depending on system
resolution). If a heat/cool overlap is specified, the displayed percent output
power is the sum of the heat power (OP1) and the cool power (OP2).
db-2 - -999 to 9999
If cooling relative gain is zero, the cooling output operates in the ON/OFF
mode, with this parameter becoming the cooling output hysteresis (positive
value only). This parameter should be set prior to Auto-Tune with cooling.
The heat/cool operation figures illustrate the effects of different deadbands.
In practice with the cooling output, observe the controlled temperature
characteristics and if the temperature remains above setpoint with a sluggish
return, increase the cooling gain. Similarly, if the temperature drops too
sharply with an overall saw-tooth pattern, decrease the cooling gain. Alter the
heat-cool overlap until a smooth response in the controlled temperature is
observed during band transition.
-40-