Honeywell SUITEPRO TB8575 - Manual (Page 15)

TB6575/TB8575 SUITEPRO™ DIGITAL FAN COIL THERMOSTATS
15 62-0278—07
BUTTON PRESS SETBACK (IS CODE #19-5)
The default remote setback option is for economy setback
via a button press on the thermostat. In this mode, the
thermostat can quickly be setback by pressing and
holding down the System Mode button for more than 3
seconds. The LCD displays ECONOMY SETBACK just to
the right of the main temperature display to indicate the
Setback is active. When any key is pressed, the
thermostat controls to Occupied mode.
REMOTE SETBACK (IS CODE #19)
Remote Setback is activated by a dry contact closure on
the remote setback input from an occupancy sensor, time
switch, or hotel card key. The thermostat controls to the
user/installer defined setback setpoints for increased
energy savings. The LCD displays Economy Setback just
to the right of the main temperature display to indicate the
Remote Setback mode is active.
When Remote Setback is active, all buttons on the
thermostat are disabled. However, the button
combinations to access Installer Setup (IS) and Installer
Test (IT) remain enabled.
ECONOMY SETBACK OPERATION
For Heat Mode, when Economy Setback is enabled, the
set point changes to the remote setback heating setpoint
(IS CODE #20).
For Cool Mode, when Economy Setback is enabled, the
set point changes to the remote setback cooling setpoint
(IS CODE #21).
For 4 pipe applications with Auto Changeover and Heat/
Cool Setpoints, when Economy Setback is enabled, the
cool setpoint changes to the remote setback cooling
setpoint and the heat setpoint changes to the remote
setback heating setpoint. The new effective deadband is
the difference between the remote setback heating
setpoint and the remote setback cooling setpoint.
Fig. 26 illustrates the relationship between setpoints,
Remote Setback, and deadband for auto changeover
with heat and cool setpoints.
Fig. 26. Auto Changeover with Heat/Cool Setpoints
deadband illustration.
For 4 pipe applications with Auto Changeover and a single
setpoint, when Economy Setback is enabled, the setpoint
will revert to a dual heat/cool setpoint approach. The
remote setback heating and remote setback cooling
setpoints will be used to create an effective unoccupied
deadband.
Fig. 27 illustrates the unoccupied deadband when
Economy Setback is enabled for 4-pipe single setpoint
auto changeover.
Fig. 27. 4 Pipe Auto Changeover with Single Setpoint
and Economy Setback Deadband Illustration
Fan Modes
VERSASPEED™ FAN RAMPING
When the fan switch is in auto, the thermostat will cycle
the fan using the fan ramping algorithm. The appropriate
fan speed is selected according to Fig. 28.
The fan ramping algorithm is illustrated in Fig. 28
Fig. 28. VersaSpeed™ fan ramping algorithm
illustration.
AUTO FAN RESET (IS CODE #24)
If Auto Fan Reset is enabled, and a constant fan speed is
selected, the thermostat resets the fan to Auto.
• Value = 1: The fan resets back to Auto after 2 hours.
• Value = 2: The fan resets back to Auto after 4 hours.
The start time is calculated after the initial call for Heat/
Cool is satisfied. Then, the two or four hour timing begins.
The fan is set back to Auto when the 2-hour or 4-hour
delay expires.
Application Modes
2 PIPE SEASONAL CHANGEOVER APPLICATIONS
These applications require the pipe sensor as a N.O,
N.C., or Analog Input to detect seasonal changeover:
• 2 pipes with auto changeover
• 2 pipes with auxiliary heat
Changeover occurs when the system has been changed
over from the boiler to the chiller. This occurs on a
seasonal basis from winter to summer months. When
using a pipe sensor as an analog input, the thermostat
can use the logic below to determine what mode to
operate in. A changeover will occur when the pipe
temperature goes above the threshold for heating or
below the threshold for cooling. If a purge has not
occurred or a call has not been satisfied in awhile, the
pipe temperature may start to get close to the ambient
temperature. In this case, the thermostat will only
changeover once the temperature falls into the opposite
threshold.
UNOCCUPIED DEADBAND
DEADBAND
REMOTE SETBACK COOL SETPOINT
UNOCCUPIED DEADBAND
COOL SETPOINT
HEAT SETPOINT
REMOTE SETBACK HEAT SETPOINT
M27562
M31331
HEAT SWITCHING POINT
REMOTE SETBACK HEAT SETPOINT
REMOTE SETBACK COOL SETPOINT
COOL SWITCHING POINT
SETPOINT
UNOCCUPIED DEADBAND
UNOCCUPIED DEADBAND
-2°F
+2°F
+4°F
-4°F
FAN SPEED IS HIGH
DIFFERENCE
BETWEEN
RT AND
SETPOINT
COOL
HEAT
SETPOINT
M27563
FAN SPEED IS MEDIUM
FAN SPEED IS LOW
FAN SPEED IS HIGH
FAN SPEED IS LOW
FAN SPEED IS MEDIUM