Hoshizaki RF28A, Руководство по обслуживанию

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32
C. Thermistor Check
A thermistor (semiconductor) is 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 Cabinet/Defrost Thermistors Clogged Filter Thermistor
0 -17.8 14.2 -
10 -12.2
10.7 -
32 0.0
6.0 160
50 10.0 3.9 100
70 21.1
2.5 59
90 32.2 1.6 36
Clogged Filter Thermistor T-R Curve
Cabinet & Defrost Thermistor T-R Curve
To check a thermistor's resistance, follow the steps below.
1) Disconnect the connector for the thermistor in question from the control box.
2) Remove the thermistor. See "IV. F. Removal and Replacement of Thermistor."
3) Immerse the thermistor sensor portion in a glass containing ice and water for 2 or 3
minutes.
4) Verify the temperature in the glass, then check for resistance between thermistor leads.
See the table above for temperature and resistance values. Normal reading is from 5
to 6.5k
Ω
for the cabinet and defrost thermistors and 145 to 175k
Ω
for the clogged filter
sensor. Replace the thermistor if it exceeds the normal reading.
Temperature °F (°C)
R
(k
Ω
)
Temperature °F (°C)
R
(k
Ω
)