Technical data

BBW 46 / DBW 46 2 General Description
203
2.5 Flame Sensor
The flame sensor consists of a photo transistor protected
by a pipe. After flame-up the pipe starts to glow so that the
sensor signals "flame". The flame sensor monitors the
flame condition throughout heater operation.
Flame Sensor
2.6 Glow Plu
g
The glow plug ignites the fuel/air mixture during heater
start.
12 Volt 24 Volt
Glow Plugs
2.7 Temperature Sensor
The temperature sensor consists of an aluminium sleeve
with an integral silicon PTC sensor.
The flame sensor senses the coolant temperature in the
heat exchanger of the heater as an electrical resistance.
The resistance changes according to temperature and
controls via the control unit the heater as well as the
vehicle air fan.
Temperature Sensor
2.8 Temperature Limiter
The temperature limiter protects the heater against undue
high operating temperatures. The temperature limiter
responds when exceeding the maximum temperature and
can be reset after cooling down.
Temperature Limiter
2.9 Temperature Fuse
The temperature fuse protects the heater against undue
high operating temperatures. The temperature fuse
includes a fusible plug which melts when exceeding the
maximum temperature. Fuel supply is interrupted and the
heater switches off. The temperature fuse must then be
replaced.
Temperature Fuse
2
4
V