User guide

Publication 900-UM007D-EN-E - January 2011
Parameter Adjustments & Application Considerations 4-13
Dead Band (Heating and Cooling Control)
When the heating and cooling control mode is selected, the Dead Band
parameter can be used. The dead band is configured with the set point as its
center (refer to Figure 4.26). The dead band width is the configured value of
the Dead Band parameter (Adjustment function group). Setting a negative
value produces an overlap band. If an overlap band is configured the bumpless
function may not operate when switching between automatic and manual
operation.
Note: The default is 0.0 EU for controllers with temperature inputs and
0.00% full scale for controllers with analog inputs.
Table 4.C — Example: 900-TC8 & 900-TC16
Parameter Name Symbol
Without Control Output 2 With Control Output 2
Standard Heating/Cooling Standard Heating/Cooling
Control Output 1
Assignment
out1 Control Output
(heating)
Control Output
(heating)
Control Output
(heating)
Control Output
(heating)
Control Output 2
Assignment
out2 Not assigned
➊ Not assigned ➊ Not assigned Not assigned
Auxiliary Output 1
Assignment
sub1 Alarm 1
➋ Alarm 1➋ Alarm 1 ➋ Alarm 1➋
Auxiliary Output 2
Assignment
sub2 Alarm 2 ➌ Control Output
(cooling)
➌
Alarm 2 Alarm 2
➊No parameter assignment is displayed because there is no control output
➋The output set for the Auxiliary Output 1 Assignment parameter becomes the program END output unless the program pattern is OFF.
➌ For the 900-TC8, the Auxiliary Output 3 Assignment parameter is set for control output (cooling) (the Auxiliary Output 2 Assignment parameter is set for alarm 2).
• The heating/cooling operation of the control outputs will switch when the Direct/Reverse Operation parameter is set to “direct.”
• When DRS (Invert Direct/Reverse Operation) is assigned for an Event Input Assignment (1 or 2), control will start with the contents set for the Direct/Reverse Operation
parameter inverted when the event input turns ON, and with the contents left according to the setting when the event
input turns OFF. For details on event inputs and control combined with the Direct/Reverse Operation parameter, refer to Control by Inverting Direct/ Reverse Operation.
This function is not supported by 900-TC32.
• When heating/cooling control is selected, the Dead Band and Cooling Coefficient parameters can be used.
Table 4.D — Example: 900-TC32
Parameter Name Symbol Standard Heating/Cooling
Control Output 1 Assignment out1 Control output (heating) Control output (heating)
Aux1 Output 1 Assignment sub2 Alarm 1
➊ Control output (cooling)
➊ The Auxiliary Output 1 Assignment parameter becomes the program end output unless the Program Pattern parameter is configured to OFF.