Viking VCBB536 - Diagnostics; Thermistor Alarm and Temperature Control; Temperature Control Operation; Thermistor Resistance Charts

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Diagnostics
Special Features (continued)
Thermistor Alarm
When the controller detects an open Thermistor circuit, the alarm sounds, freezer or refrigerator indicator
light will be displayed, and temperature indicators 4 through 7 will turn on in sequence.
To turn alarm off, press “ALARM OFF” pad, alarm will reset for normal operation. If condition has not been
corrected, alarm will sound again. Refer to Temperature Control Operation section and Electronic Testing section.
Temperature Control Operation
For any temperature setting, outputs will be turned off/on based on cut-in/cut-out temperature determined
by resistance levels of freezer or refrigerator thermistors.
Refrigerator and Freezer Thermistor (NTC)
As temperature decreases, resistance increases. As temperature increases, resistance decreases.
Note: Open thermistor or thermistor circuit will result in failure of refrigerator to cool. Shorted thermistor
will cause refrigerator to run 100 percent of time except during defrost cycle.
Deg F Deg C K-Ohms
-24 -31 565
-22 -30 531
-20 -29 499
-18 -28 469
-16 -27 441
-15 -26 415
-13 -26 391
-11 -24 368
-9 -23 347
-8 -22 327
-6 -21 308
-4 -20 291
-2 -19 274
0 -18 259
1 -17 245
3 -16 231
5 -15 218
7 -14 206
9 -13 195
Deg F Deg C K-Ohms
10 -12 185
12 -11 175
14 -10 165
16 -9 157
18 -8 148
19 -7 141
21 -6 133
23 -5 126
25 -4 120
27 -3 114
28 -2 108
30 -1 103
32097
34193
36 2 88
37384
39480
41576
43672
Deg F Deg C K-Ohms
45769
46865
48962
50 10 59
52 11 56
54 12 54
55 13 51
57 14 49
59 15 47
61 16 44
63 17 42
64 18 41
66 19 39
68 20 37
70 21 35
72 22 34
73 23 32
77 24 31
77 25 30