Repair manual

44
Figure 14
~ Control unit, slot “G” for temperature sensor
Ä Control unit, slot “C” for safety thermal cutout sensor
Removing the temperature sensor and safety thermal
cutout sensor (see Figure 14 and Drawing 28)
Drawing 28
~ Temperature sensor
Ä Safety thermal cutout sensor
Resistance [ohms]
800
1000
1200
1400
1600
1800
400
0
200
600
-40
40
080
120
Temperature [C°]
2000
Drawing 29
• Remove plug connector from the temperature sensor /
safety thermal cutout sensor on the control unit.
• Unscrew temperature sensor / safety thermal cutout sensor
from the heat exchanger.
Diagram - temperature sensor (excerpt)
Characteristic values - temperature sensor (PTC)
Temp. [°C] Impedance [Ω] Permitted deviation [±Ω]
- 40 567 18
0 815 15
25 1000 12
40 1122 16
60 1299 23
80 1490 30
100 1696 44
120 1915 52
130 2023 62
Impedances for temperature sensor and safety thermal
cutout sensor (see Drawings 29 and 30)
Check the temperature sensor and the safety thermal cutout
sensor using a digital multimeter and compare the values with
the diagram and table of characteristic values.
If the measured values do not agree with the diagram or table
of characteristic values, then replace the temperature sensor
or safety thermal cutout sensor.
Test for ground leakage:
There must be no electric connection between the sensor
connections and the casing. Impedance must be ∞.
5 / Repair Instructions
~
Ä
1
2
• Take off the hood.
• Unscrew the fan wheel in an anti-clockwise direction,
counter-restraining the motor shaft with screwdriver.