Webasto Air Top Evo 40 Workshop Manual - Function Description
Function Description
Air Top Evo 40 / Air Top Evo 55
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3
Function Description
3.1
Control element
Air Top Evo 40 / Air Top Evo 55 can be activated either with
suitable control elements, e.g. rotary selector, combination
timer, or an Air Top Evo Multi Control (MC04).
Operation is described in the operating instructions of the re-
spective control element.
The control element is used to switch the heater on and off,
to set the desired room temperature (between approx. 5 °C
and 35 °C) and the operating indicator.
The installed operating indicator is used
•
as switch-on check,
•
as a fault signal and
•
as a service display.
Additional comfort functions (Eco, Normal, Plus and Ventila-
tion) can be controlled with the Air Top Evo Multi Control
(MC04) control element.
NOTE
ADR operation:
After an ADR switch-off, the heater is in an ADR lock-out.
This is cancelled by switching the device off and then on
again.
3.2
Switching on
Switch on heater.
Set the control element to the required temperature.
The starting process begins when the room temperature is
below the setpoint temperature.
NOTE
If the room temperature is above the selected setpoint tem-
perature, only the drive motor with the combustion and heat-
ing air fan runs. When an external room temperature sensor
is connected, the drive unit does not run.
Before starting, a plausibility test of the temperature sensors
is carried out and the function of the exhaust-temperature
flame monitor is checked. If the flame monitor now reports
“light”, the system will attempt to cool the flame monitor for
up to 100 seconds. If the flame monitor still reports “light”
the control unit will suffer a fault lock-out. Also see
Section 3.10, "Fault switch-off".
Start
When the heater is switched on the operating display will be
lit and the glow plug will be switched on (cycled). The drive
motor with the combustion and heating air fan is adjusted to
approx. 50 % of the maximum speed.
After approx. 40 seconds, the fuel pump is put into operation
and flame formation begins. To improve the starting quality,
the fuel pump and the drive unit are controlled with different
frequencies and speeds.
After a further 80 to 120 seconds the glow plug will be
switched off and the existence of the flame established.
Automatic restart
If the flame monitor does not find a flame, the starting pro-
cedure will be repeated. The glow plug will be switched on
again (cycled). The drive motor with the combustion and
heating air fan is adjusted to approx. 50 % of the maximum
speed.
After approx. 40 seconds, the fuel pump is put into operation
and flame formation begins.
After a further 80 to 120 seconds the glow plug will be
switched off and the existence of the flame established.
If the heater has again failed to ignite properly, the it will be
shut down using a fault slow down procedure at maximum
speed after approx. 240 seconds and will suffer a fault lock-
out.
NOTE
After restarting, a fault lock-out of the heater is carried out.
To reset the fault switch the heater off briefly (at least 2 sec-
onds) and then on again.
3.3
Heating mode
Whilst the heater is operating the combustion gases pass
through the heat exchanger. In the process, the combustion
heat is given off to the walls of the heat exchanger, absorbed
by the cold air transported by the heating air fan and routed
into the vehicle interior.
The temperature of the cold air intake is measured by a room
temperature sensor in the control unit or an external room
temperature sensor. If the measured temperature is less than
is set on the control element, the heater output increases to
the maximum heating capacity.
To increase the burner service life in continuous operation,
the delivery capacity of the fuel pump is reduced for 10 sec-
onds every 10 minutes.
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