47
100K sensors are used for water temperature measurement. These sensors are dual thermistors in a single
sensor housing. The control uses both sensor reading in operating the unit. If the control measures tempera-
tures on these thermistors which are approx. 3F apart, the control will shut off the compressor and show “H2O
Sensor Fail”. The message will be cleared and operation resume when thermistors are within 2F of each other.
The sensor has a measurement error of less than +/- 0.5F between 36F and 110F temperatures. The control
displays 100K sensor temperatures to 0.1F or 0.1C resolution. The water temperature used for thermostat deci-
sions is the average of the 2 thermistors.
10K sensors are used for the Ambient Air Temperature sensor, the Coil Temperature sensor and Aux Heat
Temperature sensor (field supplied when necessary). The sensor has a measurement error of less than +/- 0.5F
between 36F and 110F temperatures. The control displays 10K sensor temperatures to 0.1F or 0.1C resolution.
Table I: Sensor Values
Temperature (ºF)
Resistance (
Ω
)
32
32550
41
25340
50
19870
59
15700
68
12490
77
10000
86
8059
95
6535
104
5330
113
4372
122
3605
Temperature (ºF)
Resistance (
Ω
)
32
-----
41
253950
50
199040
59
157150
68
129440
77
100000
86
80570
95
65310
104
53260
113
43680
122
36020
10K Sensor Resistance Values
100K Sensor Resistance Values
