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VisionPRO
TM
8000 Touchscreen Programmable Thermostat
37
68-0280—01
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.
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.
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.
Heat On
SCHED
HOLD
CLOCK SCREEN
MORE
MON
TUE
WED
THU
FRI
SAT
AAT
SUN
AM
FAN
AUTO
SYSTEM
HEAT
Following
Schedule
Inside
Set To
M19974
Table 13. Sensor Resistance at Room Temperature.
Room
Temperature
Ohms
of
Resis-
tance
Room
Temperature
Ohms
of
Resis-
tance
°F
°C
°F
°C
40
4.4
22537
72
22.2
11100
42
5.6
21516
74
23.3
10644
44
6.7
20546
76
24.4
10210
46
7.8
19626
78
25.6
9795
48
8.9
18754
80
26.7
9398
50
10.0
17926
82
27.8
9020
52
11.1
17136
84
28.9
8659
54
12.2
16387
86
30.0
8315
56
13.3
15675
88
31.1
7986
58
14.4
14999
90
32.2
7672
60
15.6
14356
92
33.3
7372
62
16.7
13743
94
34.4
7086
64
17.8
13161
96
35.6
6813
66
18.9
12607
98
36.7
6551
68
20.0
12081
100
37.8
6301
70
21.1
11578
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