Temperature Control Operation - Viking VCFB5301 Service Manual

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.
Freezer Thermistor (NTC)
As temperature decreases, resistance increases. As temperature increases, resistance decreases.
Note: Open thermistor or thermistor circuit or a shorted thermistor will result in freezer continuing to cool
with error code displayed. The section will call for cooling 100 percent of time except during defrost cycle
Deg F Deg C
-24 -31
-22 -30
-20 -29
-18 -28
-16 -27
-15 -26
-13 -25
-11 -24
-9 -23
-8 -22
-6 -21
-4 -20
-2 -19
0 -18
1 -17
3 -16
5 -15
7 -14
9 -13
Freezer temperature setting and thermistor value will determine if compressor/condenser fan and evaporator fan
switches are open or closed. Compressor/ condenser fan switch must be open for 6 minutes before switch can close
again (compressor dwell time). Refrigerator temperature setting and thermistor value will determine if fresh food
switch is open or closed. Cut-out and cut-in temperature values must be reached and maintained for 15 seconds
before output state will change (digital delay). Freezer control calibration can be adjusted in Program Mode A.
©2012 Viking Preferred Service
K-Ohms Deg F
565 10
531 12
499 14
469 16
441 18
415 19
391 21
368 23
347 25
327 27
308 28
291 30
274 32
259 34
245 36
231 37
218 39
206 41
195 43
Deg C K-Ohms
-12 185
-11 175
-10 165
-9 157
-8 148
-7 141
-6 133
-5 126
-4 120
-3 114
-2 108
-1 103
0 97
1 93
2 88
3 84
4 80
5 76
6 72
Operation
Deg F Deg C K-Ohms
45 7
46 8
48 9
50 10
52 11
54 12
55 13
57 14
59 15
61 16
63 17
64 18
66 19
68 20
70 21
72 22
73 23
75 24
77 25
69
65
62
59
56
54
51
49
47
44
42
41
39
37
35
34
32
31
30
11