GF83.70-W-0003C | Auxiliary heater (ZHE) - function | 18.9.97 |
MODELS 970, 972, 974, 975, 976 with CODE (H61) Webasto Air Top 2000 hot air auxiliary heater
MODELS 375.4, 944 with CODE (H61) "Webasto" Air Top 2000 hot air auxiliary heater
W83.70-0162-09
1 Auxiliary heater
3 Combustion and heated air blower
11 Fuel metering pump
12 Timer
4 Control IC
10 Heat exchanger
Function
To start up the auxiliary heater (1) the desired temperature and starting time are set on the timer (12). The starting procedure then runs automatically. The starting procedure can also be undertaken manually on the timer (12).
When the auxiliary heater (1) starts up, the controller board (4) switches on the combustion and heater air blower (3) and the heating element. After a specified time delay fuel starts to be delivered whereupon it is ignited at the heating element in the afterburner pipe by means of the aspirated combustion air. The rotational speed of the combustion and heater air blower (3) and the fuel metering pump (11) are regulated accordingly during the starting procedure.
As soon as the flame is detected by the flame monitor, the combustion procedure stabilizes and then switches over to the regulated heating mode, i.e. the maximum heating output is maintained until the aspirated combustion air from the cab has reached the specified temperature.
The auxiliary heater (1) is shut down manually on the timer (12). The auxiliary heater (1) switches into power-down, the fuel feed is terminated and the speed of the combustion and heater air blower (3) is reduced in stages until it reaches "zero".