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Controller Set
Points
Working Set Point (Heating) = Comfort Set Point (Heating) (Supervisory System)
Working Set Point (Cooling) = Comfort Set Point (Cooling) (Supervisory System)
The set point in all control modes may be modified from the integrated
set point adjuster or from the remote set point dial/control panel on the
Room Command Module, according to the controller model type. The
controller models with a remote set point of 12-28°C require that a Room
Command Module or an external potentiometer is connected to give the
set point. Controllers with a remote set point of +/-3 K have internal
factory set points of 20°C for heating and 22°C for cooling.
The set point is decreased or increased in the STANDBY control mode
by the factory-set "Standby Bias Heating" and "Standby Bias Cooling"
values to reduce the heating or cooling energy required when the room is
temporarily unoccupied.
When a supervisory system is connected, the set point can be further
decreased or increased in the NIGHT control mode to further reduce
energy requirements during scheduled unoccupied periods such as nights,
weekends and holidays.
In the controller there are two "comfort" set points (Comfort Set Point
Heating and Comfort Set Point Cooling), and the difference between
these two values determines the zero energy band where neither heating
nor cooling is required. The controller calculates two working set points
(WSP Heating and WSP Cooling), which are the sum of the comfort set
point values, the "Remote Set Point" value coming from the integrated
set point adjuster or the Room Command Module, and the "Common Set
Point" value. In the supervisory mode an adjustment may be made to the
working set points either by changing the "Comfort Set Points," or by
changing the value in the "Common Set Point" parameter of the
controller which enables the supervisory system operator to adjust the
setpoints for heating and cooling at the same time without affecting the
zero energy band. In summary:
+ Remote Set Point (integrated adjuster or Command Module dial)
+ Common Set Point (Supervisory System)
+ STANDBY or NIGHT Bias Heating (if mode is active)
+ Remote Set Point (integrated adjuster or Command Module dial)
+ Common Set Point (Supervisory System)
+ STANDBY or NIGHT Bias Cooling (if mode is active)
When the room temperature is below the working set point for heating,
the heating output increases according to the proportional band and
integral time parameters set for the heating control loop. When the room
temperature is above the working set point for cooling, the cooling output
increases according to the proportional band and integral time parameters
set for the cooling control loop. Heating and cooling control is illustrated
in figures 8 and 9.
Technical Bulletin—TC-9102
7
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