2.7 Temperature Limiter
The temperature limiter protects the air heater against
excessive operating temperatures. Overheat protection
is activated at a temperature higher than 150 °C to inter-
rupt the electrical circuit of the dosing pump and switch
off the heater with run-down operation.
After cooling down the electrical circuit is restored.
The air heater may be switched on again (see 3.1.8).
Temperature Limiter
2.8 Dosing Pump
The dosing pump is a combined supply, dosing and shut-
off system for the fuel supply of the heater out of the
vehicle’s fuel tank.
Dosing Pump DP 2 for Gasoline and Diesel
operated Heaters
Dosing Pump DP 30 for Diesel operated Heaters
203
2.5 Flame Sensor
The flame sensor is a low-Ohm PTC resistor changing
its resistance dependent on its heating by the flame.
The signals are routed to the control unit for processing.
The flame sensor monitors the flame operating condition
over the complete duration of heater operation.
Flame Sensor
2.6 Glow Plug
The glow plug ignites the fuel/air mixture at the start of
the air heater operation. The glow plug is acting as an
electrical resistor and is located in the burner insert
opposed to the flame side.
Glow Plug
2 General Description
Air Top 2000 S
