Webasto Air Top 2000 ST D Service And Repair Manual - page 28
Webasto Product N.A., Inc.
28
www.techwebasto.com
SERVICING WORK
AIR TOP 2000 ST
CAUTION: In vehicles used to transport
people, the air outlet opening is to be
installed in such a way that it is at least 20
cm away from all body parts.
The heater checks the internal temperature rise
automatically each time it is switched on. If this is above
the specified limits, the start is cancelled and error
messages F10 is displayed. To ensure that the heater
functions stably, the flow resistance of the connected hot
air system must be reduced.
If a filter is used for the hot air, it must have the following
properties:
•
The air flow must not carry any inflammable and/or
harmful fibers or particles into the heater or the
interior of the vehicle.
•
The filter material must be able to withstand
temperatures of at least 60 °C.
•
The filter must be resistant to all the substances that
may be drawn in with the hot air (for example
moisture, salt, fuel vapors, etc.).
•
The resistance of the filter must be taken into
consideration when designing the hot air system.
8.6.2
F
UEL
S
UPPLY
The fuel is taken from the vehicle fuel tank or from a
separate fuel tank. The values for the maximum pressure
at the fuel extraction point are shown in Fig. 15.
8.6.2.1 F
UEL
E
XTRACTOR
(S
TANDPIPE
)
Vehicles with Diesel Engines
The fuel must be taken from the vehicle fuel tank or from
a separate tank (Fig. 16, 17 or 18). This separate fuel
pickup precludes any effect of pressure.
Vehicles with injection Engines
When installing the heater in a vehicle with fuel injection
systems, it is important to establish whether the fuel
pump is located inside or outside the tank.
If the fuel pump is located inside the tank, fuel can only
be extracted from the return line using a Webasto fuel
tee fitting in which case it must be ensured that the
return line continues almost to the bottom of the tank. If
this is not the case, a Webasto fuel standpipe
(see Fig. 16, 17 or 18) may be used.
If the fuel pump is installed outside the tank, the fuel
connection may also be made between the tank and the
fuel pump, again using only the Webasto fuel tee fitting.
Vehicles with Carburetor Engines
The fuel may only be extracted on cars using a special
Webasto fuel tee fitting as close to the tank as possible.
The connection may be made in either the supply or
return line, in which case the return line must lead almost
to the base of the tank. If this is not the case, the return
line may be extended.
The fuel tee must be fitted in such a way that any air or
gas bubbles are automatically discharged towards the
tank.
The fuel tee should not be located near the engine, as
gas bubbles may form in the lines on account of heat
radiated from the engine. This may cause problems
during combustion.
Permissible fuel inflow
height H (m)
At max. pressure (bar) in
fuel line
0.00 m (0.00 in.)
0.20 bar (2.9 PSI)
1.00 m (39.4 in.)
0.11 bar (1.6 PSI)
2.00 m (78.7 in.)
0.03 bar (0.44 PSI)
Maximum fuel intake
height S (m)
At max. negative pressure
(bar) in fuel tank
0.00 m (0.00 in.)
-0.10 bar (-1.45 PSI)
0.50 m (19.7 in.)
-0.06 bar (-0.87 PSI)
1.00 m (39.4 in.)
-0.02 bar (-0.29 PSI)