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— Users cannot make changes to the temperature setpoint or
any schedule, system, or fan settings.
— The only features available are HOLIDAY and OVERRIDE.
— To unlock the screen, see Advanced Settings section.
Temperature Recovery
The thermostat is equipped with a feature to eliminate
guesswork when setting a schedule. That is, the user need not
know the amount of time for the HVAC system to bring the
space to temperature (without overshoot) prior to the
scheduled time.The thermostat manages that automatically.
Simply set the program schedule to the desired time to have
the space at comfort temperature. In addition, program the
temperature to this comfort temperature. The thermostat
activates the heating or cooling at the proper time to reach the
scheduled temperature at the scheduled time.
NOTE: The setpoint changes gradually to use economical
stages and avoid overshoot.
For example—the space will be occupied at 8:00 AM and the
desired temperature is 70°F. Set the OCC 1 period for 8:00 AM
and 70°F. The thermostat turns on the heat prior to 8:00 AM to
raise the temperature to 70°F by 8:00 AM.
The thermostat provides an alert that the heating or cooling
system is coming on before a scheduled time by displaying
"Recovery" on the screen.
Minimum-Off Timer Compressor Protection
The thermostat has an adjustable Minimum-Off Timer that can
be set from zero to five minutes (Factory Setting—five
minutes). The Minimum-Off Timer can be bypassed through
the Installer System Test or it can be bypassed permanently by
setting the Minimum-Off Timer to 0 minutes in the Installer
Setup. The Minimum-Off Timer is activated after the
compressor turns off:
— If the thermostat is system powered (common wire), the
Minimum-Off Timer is also activated upon initial startup and
after power interruptions.
— If there is a call for cooling or heating during the Minimum-
Off Time, the thermostat displays "Wait."
— When the Minimum Off Timer expires, "Cool On" or "Heat
On" (heat pumps only)" appears solidly in the display and
the compressor and fan turn on.
Temperature Sensor Operation and Checkout
Allow outdoor or indoor temperature sensor to absorb the air
for a minimum of five minutes before taking a reading. See the
Sensor instructions for more information.
NOTE: The C7189U, TR21 and TR21-A Temperature
Sensors are calibrated at the factory and cannot
be recalibrated in the field.
C7189U Remote Indoor Temperature Sensor
Operation
When installed with Thermostat ISU 0340 set to 3, the remote
inside temperature is displayed on the Thermostat Home
Screen as Inside Temperature. The thermostat internal
temperature sensor is not used.
TB7100A1000 MULTIPRO™ MULTISPEED AND MULTIPURPOSE THERMOSTAT
The C7189U can be used to provide one remote sensor input
or as a temperature averaging network with multiple TR21
Sensors connected, as shown in Fig. 28.
Checkout
For best results, allow C7189U Wall Mount Temperature
Sensor to absorb the air moving through the room for a
minimum of twenty minutes before taking a resistance
measurement.
With an accurate thermometer (±1°F [0.5°C]) measure the
temperature at the sensor location, allowing time for the
thermometer to stabilize before reading.
To verify sensor resistance, remove one wire from one of
C7189U wiring terminals. Use an ohmmeter to measure the
resistance across the sensor. Then compare sensor accuracy
with the temperature/resistance curve in Fig. 40.
Fig. 40. 10K ohm sensor resistance versus temperature.
TR21 Remote Temperature Sensor
Operation
When installed with Thermostat ISU 0340 set to 3 or 4, the
remote inside temperature is displayed on the Thermostat
Home Screen as Inside Temperature. The thermostat internal
temperature sensor is not used.
The TR21 can be used to provide one remote sensor input or
as a temperature averaging network with multiple TR21
Sensors connected, as shown in Fig. 25 through 27.
Checkout
For best results, allow TR21 Wall Mount Temperature Sensor
to absorb the air moving through the room for a minimum of
twenty minutes before taking a resistance measurement.
With an accurate thermometer (±1°F [0.5°C]) measure the
temperature at the sensor location, allowing time for the
thermometer to stabilize before reading.
To verify sensor resistance, remove one wire from one of the
wiring terminals. Use an ohmmeter to measure the resistance
across the sensor. Then verify the sensor accuracy with the
temperature/resistance in Fig. 41.
21
220K
190K
160K
130K
100K
90K
60K
30K
0K
-40
-20
0
20
40
60
-40
-30
-10
0
-20
10
TEMPERATURE (DEGREES)
10K OHM AT
77
o
F (25
o
C)
80
100
120
o
F
30
40
50
o
C
20
M22823
63-2675—01
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