General
The heater unit is the central component of the stationary heater. It comprises all components necessary for generating heat.
Function requirements
Circuit 30t ON
Stationary heater switched on
Fuel level above fuel reserve
No overvoltage or undervoltage
Interior and outside temperature have been determined.
Structure
The stationary heater unit (1) is located in front of the front right wheel arch. It essentially consists of the stationary heater control unit (1.1), the combustion-air blower (1.2) and the burner housing (1.3).
1 | Stationary heater unit |
1.1 | Stationary heater control unit |
1.2 | Combustion air blower |
1.3 | Burner housing |
P83.70-5756-82
Function
The stationary heater control unit (1.1) starts the heating mode by actuating the combustion-air blower (1.2) in the heater (1). It also actuates the glow plug/flame monitor unit and starts a preglow time of approx. 30 s. After expiry of the preglow time, the stationary heater control unit (1.1) actuates the fuel pump directly and the fuel feed starts. The fuel evaporates on a metallic mesh in the burner housing (1.3) and, together with the combustion air, forms a fuel/air mixture, which ignites on the glow plug. A flame is produced which heats the coolant. During heating mode, the glow plug/flame monitor unit performs the function of the flame monitor.
If the flame monitor detects an insufficient temperature (flame failure or insufficient flame formation), the stationary heater control unit (1.1) switches off the stationary heater fuel pump. It then initiates a one-off re-start. If flame formation is still not possible, the stationary heater control unit (1.1) switches off the stationary heater fuel pump and activates the emergency shutoff function with run-on of the combustion-air blower (1.2).
A temperature sensor in the heater (1) measures the temperature in the heater (1). The stationary heater switches off from a temperature of approx. 125 °C. The stationary heater fuel pump also switches off from a temperature of approx. 145 °C.