3.2.9 Switch-off upon Failure
The control unit recognises failures of individual air
heater components and malfunctions in the start se-
quence and in normal operation.
The air heater is deactivated and enters the error loc-
kout mode under the following conditions:
l
flame sensor open or short circuit
l
temperature sensor open or short circuit
l
glow plug open or short circuit
l
fan motor open or short circuit or fan speed wrong
l
dosing pump open or short circuit
l
overheating
l
low voltage below 10 Volt or high voltage above
15 Volt in excess of 20 seconds for 12 Volt heaters
l
low voltage below 20 Volt or high voltage above
30 Volt in excess of 20 seconds for 24 Volt heaters
A switch-off like in “switch-off” will be performed.
In case of overheating there will be no fuel supply. After
run-down the control unit is in the error lockout mode.
The operation indication outputs a flash code.
For error unlock the air heater has to be switched off
momentarily (at least 2 seconds) to be switched on
306
3 Functional Description
Air Top 2000