Hubbell ETXA Series, Описание, установка и руководство по эксплуатации, Страница: 37 / 52

37
Check the Thermistor:
1. The thermistor is a temperature sensing device that changes resistance with changes in
temperature. It is designed to register 150,000

at 25°C (77°F).
2. Set the unit to diagnostic mode by pressing and releasing the UP and DOWN buttons
simultaneously.
3. With a thermometer, measure the temperature of the cold water and hot water at a
fixture.
4. Compare the displayed inlet temperature (i###) to the measured cold water
temperature and the displayed outlet temperature (o###) to the measured hot water
temperature. If either of these readings is significantly different, continue with the
next step. Otherwise, proceed to Check the Flow Meter.
5. At the right-hand side of the temperature controller
are two terminal blocks JP1 and JP2. Disconnect
the wires from the uppermost terminal block JP2
(outlet thermistor). Using the multi-meter probes
with the setting at OHM or

, place one probe on
the end of one wire and the other probe on the end
of the other wire. An ohm reading consistent with
the chart below for the approximate temperature of
the water should be indicated. NOTE: Alligator
clips should be used. Holding the wires in your
hands will give a false reading. Reconnect the
wires.
6. Repeat the above step with the lower terminal block
JP1 (inlet thermistor).
7. If either of these readings is not consistent with the
chart (within ±10,000

), replace that thermistor.
8. If all ohm readings are acceptable, proceed to Check
the Flow Meter.
Thermistor Chart (150,000

@ 25°C (77°F))
Temperature, °F (°C)
Ohms,

50 (10.0) 299,516
60 (15.6) 229,905
70 (21.1) 178,244
80 (26.7) 139,501
90 (32.2) 110,157
100 (37.8) 87,723
110 (43.3) 70,418
120 (48.9) 56,957
130 (54.4) 46,402
140 (60.0) 38,062
150 (65.6) 31,425
160 (71.1) 26,106
170 (76.7) 21,816
180 (82.2) 18,333
190 (87.8) 15,489
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
50 60 70 80 90 100 110 120 130 140 150 160 170 180 190
Inlet
Thermistor
Outlet
Thermistor