Norcold 121X series, Service Manual

Page: 21 / 100

S
ection
3
19
1. Disconnect the thermistor from the circuit and
fin assembly. See Figure 3-9.
2. Connect a resistance meter as shown.
3. Record reading with thermistor at ambient
temperature.
4. Put the thermistor in small container filled with
crushed ice. See Figure 3-10.
5. Compare thermistor resistance changes
to temperature values shown in Table.
Thermistor Temperature to Resistance Values.
Checking thermistor resistance in ice bath
MIN MAX RANGE HOLD H
Hz REL
mA
A
mV
V
V
OFF
!
!
A COM
V
mA µ A
1000V MAX
400mA MAX
FUSED
10A MAX
FUSED
PEAK MIN MAX
µ A
CAT II
4 1/2 DIGITS
1 Seconds
87 TRUE RMS MULTIMETER III
Temperature Resistance
°C °F kohms
29 85 8.1-9.0
27 80 9.1-10.0
24 75 10.1-11.0
21 70 11.1-12.0
16 60 12.1-13.0
10 50 15.5-16.5
4 40 22.5-23.5
2 35 24.5-25.5
0.5 33 28.5-29.5
0.0 32 30.0-32.0
Table. Thermistor Temperature/Resistance Values.
Container with crushed ice
Thermistor
Connector
Thermistor
Light connections
Location: on the second fin from right
side of fin assembly
Figure 3-9. —Thermistor / light wires assembly.
Meter set to kohm scale
WIres color
THERMISTOR:
Red/White stripe
Red
LIGHT
Black /White stripe
White/Black stripe
Figure 3-10. —Checking thermistor resistance.