Webasto Thermo Top Z Shop Manual page 14

3 Functional Description
3.2 Functional Description
Thermo Top E and C (Auxiliary Heater)
3.2.1 Switch On
Fuel
When operating the "instant heat" switch button the timer
display shows or when operating the switch on the
Telestart transmitter the operating indicator light on the
transmitter flashes. This puts the heater in standly.
The glow plug, the combustion air fan and the circulation
pump are activated. After 30 seconds the fuel dosing
pump starts operation and combustion air fan operation is
suspended for 3 seconds.
Subsequently the combustion air fan speed is increased
in a ramp within 57 seconds to nearly full load operation.
After reaching full load fuel delivery within this period the
glow plug is deactivated and the combustion air fan
operation increased to full load.
During the subsequent 45 seconds as well as in normal
operation the glow plug functions as flame sensor to
monitor the flame condition.
After all these events the automatically controlled heating
operation starts. In case of a no flame condition or a
flameout, a restart is automatically initiated. If the no flame
condition persists, fuel delivery is stopped and the heater
enters an error lockout with a run-down of the combustion
air fan.
Diesel
When operating the "instant heat" switch button the timer
display shows or when operating the switch on the
Telestart transmitter the operating indicator light on the
transmitter flashes. This puts the heater in standby.
The glow plug, the combustion air fan and the circulation
pump are activated. After 30 seconds the fuel dosing
pump starts operation and combustion air fan operation is
suspended for 3 seconds.
Subsequently the combustion air fan speed is increased
in two ramps within 56 seconds to nearly full load
operation. After a stabilisation phase (constant speed) of
15 seconds the combustion air fan speed is again
increased in a ramp within 50 seconds to nearly full load.
After reaching full load fuel delivery the glow plug is
deactivated and the combustion air fan operation
increased to full load.
During the subsequent 45 seconds as well as in normal
operation the glow plug functions as flame sensor to
monitor the flame condition.
After all these events the automatically controlled heating
operation starts. In case of a no flame condition or a
flameout, a restart is automatically initiated. If the no flame
condition persists, fuel delivery is stopped and the heater
enters an error lockout with a run-down of the combustion
air fan.
A flameout during normal combustion operation causes
an automatic restart.
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Thermo Top E and Z/C
3.2.2 Heating Operation
Fuel
When the temperature rises to reach 72° C the heater
switches to the energy saving part load operation. A rise
in temperature up to 76.5° C causes the heater to enter a
control idle period. This also happens when exceeding a
total heating operating time of 76 minutes.
The circulation pump, the vehicle's own heating air fan,
and the operation indicator light remain on during control
idle.
After cool-down of the coolant to 71° C the heater
resumes part load operation. Another rise in temperature
to 76.5° C causes the heater to enter again the control idle
period. A drop in the coolant temperature during part load
operation due to an increased demand in heat will cause
the heater to switch to full load operation at 56° C.
Diesel
Heating operation for the Diesel type heater is identical in
the sequence of events. Should the coolant temperature
however not drop within 900 seconds during the control
idle period to below 71° C, a subsequent drop in the
coolant temperature below 71° C causes the heater to
perform a regular starting sequence into full load
operation.
3.2.3 Switch Off
When turning the heater off by pushing the "instant heat"
switch button ( in indicator panel extinguishes) or
when operating the switch on the Telestart (flashing
indicator on hand-held transmitter extinguishes) the
vehicle heating air fan stops.
Combustion terminates and run-down commences. The
circulation pump and the combustion air fan first continue
operation to cool the heater down (run-down) to be
automatically switched off afterwards.
NOTE
The run-down time and the combustion air fan speed
depend on the heater operating condition at the time of
deactivation.
Run-down time is for:
Fuel
168 seconds when deactivated in full load operation and
157 seconds when deactivated in part load operation.
Diesel
175 seconds when deactivated in full load operation and
100 seconds when deactivated in part load operation.
Dependent on the software variant implemented in the
control unit there might be deviations from those run-down
periods.