Hoshizaki TempGuard FH1-SSB, Service Manual, Page: 30 / 63

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B. Thermistor Check
Thermistors (semiconductors) are used for the cabinet control sensor and defrost
termination sensor. The resistance varies depending on temperature. No adjustment is
required. If necessary, check for resistance between thermistor leads and visually check
the thermistor mounting.
Temperature
Resistance k
Ω
°F °C
0 -17.8 13.69
10 -1. 10.48
3 0.0 6.00
50 10.0 3.96
70 1.1 .57
90 3. 1.71
To check a thermistor for resistance, follow the steps below.
1) Turn power off and disconnect connectors K3 and K4 on the board.
) Remove the thermistor.
3) Immerse the thermistor sensor portion in a glass containing ice and water for or
3 minutes.
4) Check for a resistance between thermistor leads. Normal reading is within 3.5 to 7 k
Ω
.
Replace the thermistor if it exceeds the normal reading.