Honeywell VisionPRO 8000 Product Data page 37

C7189U Remote Indoor Temperature Sensor
Operation
When installed with Thermostat Installer Setup Number 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. See Fig.
36.
MON TUE WED
FAN
Inside
AUTO
SYSTEM
HEAT
AM
SCHED HOLD CLOCK SCREEN
Fig. 36. Inside temperature reading on
TH8000 Series Thermostat.
The C7189 Wall Mount Temperature Sensor converts room
temperature to a resistance that the thermostat can interpret.
The C7189 has a negative temperature coefficient (NTC),
which means that resistance decreases as the temperature
increases. See Table 13.
The C7189 can be used to provide one remote sensor input
(see Fig. 28) or as a temperature averaging network with
multiple C7189 Sensors connected, as shown in Fig. 29.
Checkout
For best results, allow C7189 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.
THU FRI SAT A A T SUN
Set To
Heat On
Following
Schedule
MORE
M19974
TM
VisionPRO 8000 Touchscreen Programmable Thermostat
To verify sensor resistance, remove one wire from one of
C7189 wiring terminals. Use an ohmmeter to measure the
resistance across the sensor. Then verify the sensor accuracy
with the temperature/resistance in Table 13.
Calibration
The C7189 Wall Mount Temperature Sensor is calibrated at
the factory and cannot be recalibrated in the field.
Table 13. Sensor Resistance at Room Temperature.
Room
Temperature
°F °C
40 4.4
42 5.6
44 6.7
46 7.8
48 8.9
50 10.0
52 11.1
54 12.2
56 13.3
58 14.4
60 15.6
62 16.7
64 17.8
66 18.9
68 20.0
70 21.1
37
Ohms Room
of Temperature
Resis-
tance °F °C
22537 72 22.2
21516 74 23.3
20546 76 24.4
19626 78 25.6
18754 80 26.7
17926 82 27.8
17136 84 28.9
16387 86 30.0
15675 88 31.1
14999 90 32.2
14356 92 33.3
13743 94 34.4
13161 96 35.6
12607 98 36.7
12081 100 37.8
11578 —
Ohms
of
Resis-
tance
11100
10644
10210
9795
9398
9020
8659
8315
7986
7672
7372
7086
6813
6551
6301
68-0280—01