PLANAR
Edition 1
March 2016
Page. 19 of 29
5.4 Functions, Removal and Replacement of Temperature Sensors (PLANAR-8DM).
5.4.1 Since January 2015, PLANAR-8DM heaters are equipped with a temperature
sensor for heated air.
The sensor is installed at the heated air outlet and is connected to the CU.
Disassembly is performed in accordance with Section 5.
Sensor performance (with power applied to the heater) can be determined by the
output voltage.
The output voltage at 0°C is –2,73V. Voltage increases with temperature. As the
temperature increases by 1°C, the output voltage will increase by 10mV. Compare the
room temperature and the corresponding voltage outputted by the sensor.
If the sensor gives incorrect voltage, it is necessary to replace the sensor.
To avoid mistakes when evaluating performance of the sensor, it is necessary to
substitute it with a known-good. If the cause of heater failure is eliminated with the
installation of the new sensor, then the old sensor is considered to be inoperable and has to
be replaced.
When replacing the temperature sensor, installation is in the reverse sequence. If the
problem persists, replace the control unit to a known-good.
Fig.10–Sensors.
5.4.2 From October 2015, heaters are equipped with an additional heated air
temperature sensor.
The sensor is checked as described in 5.4.1.
