Sequences Of Operation; Room Temperature Setpoints; Occupancy; Automatic Cooling And Heating Changeover - Daikin BACnet Series Installation Manual

Sequences of Operation

Topics in this section cover the sequences of operation for the BACnet™
Thermostat. These are advanced topics for control's technicians
and engineers.

Room Temperature Setpoints

There are three temperature setpoints each for heating and cooling for
a total of six setpoints.
• Active cooling
• Occupied cooling
• Unoccupied cooling
• Active heating
• Occupied heating
• Unoccupied heating
Types of Setpoints
Active setpoint – The active setpoint is the current setpoint. The active
setpoint is determined by the following.
• If the space is occupied, the controller uses the occupied setpoint
• If the space is unoccupied the controller uses the unoccupied
setpoint
• A user with Password 1 can enter an active setpoint from the
display. This change is for a limited time or until the next time the
space status changes from unoccupied to occupied
Occupied setpoint – A temperature setpoint entered by the controls
technician during controller setup and system commissioning. This
is the setpoint used when the system is occupied which is usually
controlled by the schedule in the controller.
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 which is usually
controlled by the schedule in the controller.
Setpoint Limits
No cooling setpoint can be higher than any heating setpoint.
If a user is adjusting a setpoint and it comes with the range set by
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.
IO-DAPPS

Occupancy

The BACnet Thermostat is designed to operate as a stand-alone
controller and can determine occupancy based on its internal
occupancy schedule. The two occupancy states of the BACnet
Thermostat are Occupied and Unoccupied. An occupancy state can
also be commanded by another BACnet controller on the building
automation network.
Occupied
If the internal schedule is enabled, the state of the schedule is set to
either occupied or unoccupied as the initial state.
Unoccupied
The unoccupied state is entered only if the internal occupancy schedule
is enabled and if the schedule is inactive.
Automatic Cooling and Heating
Changeover
The BACnet Thermostat can be set to automatically change between
the heating and cooling modes.
• If the space temperature rises above the active cooling setpoint,
the mode is set to cooling
• If the space temperature falls below the active heating setpoint,
the mode is set to heating

Schedules

The internal occupancy schedule changes the BACnet Thermostat
between the occupied (active) and unoccupied (inactive) states.
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