Rheem Raypak 2450, Installation And Operation Manual

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100KOhm sensors are used for water temperature
measurement. These sensors are dual thermistors in
a single sensor housing. The control uses both sensor
readings in operating the unit. If the control measures
temperatures on these thermistors which are approx. 3°F
(1.6°C) 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 2°F (1.1°C) of each other. The sensor
has a measurement error of less than +/- 0.5°F (0.3°C)
between 36°F and 110°F (2.2°C and 43°C) temperatures.
The control displays 100K sensor temperatures to 0.1°F
or 0.1°C resolution. The water temperature used for
thermostat decisions is the average of the 2 thermistors.
10KOhm 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 +/- 0.5°F (0.3°C) between 36°F and 110°F (2.2°C
and 43°C) temperatures. The control displays 10K sensor
temperatures to 0.1°F or 0.1°C resolution.
Table J. Sensor Values
Temperature ºF (ºC) Resistance (Ω)
32 (0) 32550
41 (5) 25340
50 (10) 19870
59 (15) 15700
68 (20) 12490
77 (25) 10000
86 (30) 8059
95 (35) 6535
104 (40) 5330
113 (45) 4372
122 (50) 3605
Temperature ºF (ºC) Resistance (Ω)
32 (0) -----
41 (5) 253950
50 (10) 199040
59 (15) 157150
68 (20) 129440
77 (25) 100000
86 (30) 80570
95 (35) 65310
104 (40) 53260
113 (45) 43680
122 (50) 36020
Other Sensors
10K Sensor Resistance Values
Water Sensor
100K Sensor Resistance Values
26. RESISTANCE SENSOR VALUES