Active setpoint
—The active setpoint is the current setpoint. The active setpoint is
determined by the following.
l
If the space is occupied, the controller uses the occupied setpoint as the active
setpoint.
l
If an STE-6014 and STE-6017 is connected, the Active setpoint is set by the dial to be a
few degrees above or below the Occupied setpoint. The range of adjustment is set by
the variable STBY OFFSET. The dial setting does not change the setpoint when in the
Unoccupied or Standby state.
l
If the space is unoccupied the controller uses the unoccupied setpoint as the active
setpoint.
l
If controller is in standby, the controller calculates the standby setpoint.
l
A user with Password 1 can enter an active setpoint from a SimplyVAV digital wall
sensor. This entry will change the occupied setpoint within the setpoint limits.
Occupied setpoint
—A temperature setpoint entered by the controls technician during
controller setup and system commissioning. This is the setpoint used when the controller is
occupied which is determined by primary airflow and, on controllers equipped with motion
sensors, motion in the zone.
Unoccupied setpoint
—A temperature setpoint entered by the controls technician during
controller setup and system commissioning. This is the setpoint used when the system is
unoccupied .
Standby setpoint
—The standby setpoint is used when the controller is in the standby state.
It is a value calculated from the occupied setpoint and the variable STBY OFFSET. The
standby offset value is entered by the controls technician during controller setup and system
commissioning. See the topic
Setpoint limits
The programming in the controller limits the setpoint entry so that no heating setpoint is set
higher than its corresponding cooling setpoint.
If a user is adjusting a setpoint and it falls within the range set by the value of Minimum
Setpoint Differential, the corresponding setpoint will be changed to maintain the differential.
For example, the Minimum Setpoint Differential is 4° F and the Occupied Heating setpoint is
70° F. If the user lowers the Occupied Cooling setpoint to 71° F, the controller recalculates
the Occupied Heating setpoint and changes it to 67° F.
PID control loops
A PID control loop calculates an error value from the difference between the measured room
temperature and the active setpoint. The error value is expressed as a percentage and is
typically used in a BAS controller to control the state of an output. When the difference
between the setpoint and room temperature is large, the error is large. As the system
reduces the difference between the setpoint and space temperature, the error becomes
smaller.
Section 7: Sequences of operation
KMC Controls, Inc.
52
Revision H
Summary of Contents for SimplyVAV BAC-8001
Page 1: ...SimplyVAV Application and Installation Guide Revision H ...
Page 12: ...Section 1 About the controllers KMC Controls Inc 12 Revision H ...
Page 48: ...Section 6 Application drawings KMC Controls Inc 48 Revision H ...
Page 62: ...Section 7 Sequences of operation KMC Controls Inc 62 Revision H ...
Page 72: ...Appendix A K factors KMC Controls Inc 72 Revision H ...
