Repair work at the inner and outer chamber
7.9 Checking and replacing the inner chamber Pt 100 temperature
sensor (-3B1)
Spare parts:
Temperature sensor, 2 x Pt100
order no. 5002-0050
Sensor holder
order no. 4020-0643
Screwed cable fitting
order no. 6002-0397
Cable access port
order no. 6005-0117
PU foam
order no. 1004-0009
Necessary tools
Crosstip screwdriver, size 2
Multimeter measuring device
Fork wrench, size 15/18
Universal cutter
Side cutter
1.
Disconnect the unit from the power supply.
2.
Remove the housing cover of the lower front (chap. 5.1).
3.
Pull the bottom electric mounting plate out of the unit (chap. 8.5).
4.
Pull the wires of the Pt100 temperature sensor out of the terminal strip E1-Pt100 and the Safety con-
troller Pt100 entry on the MB1controller MB1 I/O-board (-3N2) (see wiring diagram and chap. 8.6).
Terminal strip on the controller MB1 I/O-board (-3N2) Pin
Temperature sensor wire
E1-Pt100
+1
white
-2
blue
3
blue
Safety controller Pt100 entry
1
white-blue
2
red-blue
3
red
Table 2: Connection of the Pt100 temperature sensor (-3B1) on the controller MB1 I/O-board (-3N2)
Checking the temperature sensor (-3B1):
5.
To test the temperature sensors, measure the resistance with a multimeter between one of the blue
wires and the white wire (for Pt100 inner chamber), resp. between the white-blue wire and the red or
the red-blue wire (for Pt100 safety controller).
6.
Refer to Table 1 for the temperature value of the respective measured resistance value. Compare this
temperature value with the temperature measured with a reference thermometer measuring the tem-
perature inside the inner chamber. If the temperature values deviate by < 5°C, perform an adjustment
(chap.11). If the temperature values deviate by more than 5°C, the temperature sensor is defective
and must be replaced.
7.
Remove the inner chamber (chap. 7.7).
8.
Remove the cable access port of the Pt100 temperature sensor from the left spoiler.
9.
Remove the left spoiler (chap. 7.7).
Service Manual KBF (E5.2) 04-2015
69