GE GUD24ESSMWW, Technical Service Manual

Page: 57 / 81

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Resistance can be measured at the J701 main
board connecter. Make sure to unplug the connector
to isolate the thermistor before taking resistance
readings. To determine the temperature of the
incoming water, the main control measures the
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voltage returned from the thermistor. The main
board then makes temperature adjustments
accordingly.
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/- 10°F to 15°F of set temperature by
opening or closing the hot and cold water valves.
The Automatic Temperature Control (ATC) is a
feature that utilizes a thermistor to regulate the
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The thermistor has a negative temperature
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decreases).
The thermistor is located in the outlet of the
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:
at room
temperature (77°F / 25°C).
If the thermistor reads outside the expected range
(10k to 120k
:
), the main control will default to the
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between 60°F and 135°F:
‡ Tap Cold : Cold water valve only
‡ Cold : Cold water valve only
‡ Cool : Hot and cold water valves
‡ Warm : Hot and cold water valves
‡ Hot : Hot water valve only
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hot ratio.
With the lid open, ATC is deactivated.
Extreme water temperatures at low pressure can
cause the ATC to use its maximum number of
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main control will not allow the water valve to cycle
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(Continued Next Page)
ATC Temperature Chart
Temperature Setting Water Temperature
Tap Cold Cold Tap Water
Cold 60°F (+/- 10°F)
Cool 70°F (+/- 10°F)
Warm 80°F (+/- 10°F)
Hot 110°F (+/- 15°F)
Automatic Temperature Control (ATC)
Thermistor Resistance Table
Temp ( ° C) Temp ( ° F) Resistance (
:
)
10 50 96,369
15 59 78,033
20 68 61,918
28 82.4 43,754
32 90 37,286
38 100 28,987
44 111 22,954
50 122 18,223
54 130 15,672
66 150 10,196
76 169 7,265