Installing The Metering Pump; Fuel Connection; Safety Instructions For Routing Fuel Lines - Truma Combi D 6 Einbauanweisung

The 4 muffs on the unit are designed for the 65 mm diameter
ÜR duct (part no. 40230-00). Use only pressure-safe ducts
in compliance with Truma quality requirements. Other ducts
that do not meet our quality standard (particularly with regard
to crown pressure resistance, ducts diameter and number of
grooves) must not be used.
If the warm air pipe has to be heavily bent directly behind the
warm air outlet due to a lack of space, we recommend the use
of a 90° elbow BGC (part no. 34091-01). This elbow makes
it possible to connect a ÜR warm air duct with a diameter
of 65 mm or a VR warm air duct with a diameter of 72 mm.
With a duct length of less than 2 m the air outlet must not
be installed higher than the warm air duct muff. With a duct
length of less than 50 cm, the duct must create a siphon be-
tween the muff and the outlet.
L ≤ 50 cm
These measures prevent undesirable heating of the vehicle
due to convection (cowl effect) during operation in summer.
The ducts for warm air distribution must be inserted securely
into the muff. A clip is attached to each muff to provide a
more secure grip.
In order to prevent heat accumulation when using the
Combi D 6, all 4 warm air connecting pieces must be
attached. The cross-section of the hot air pipes must not be
reduced by pipe connections or the like. If an EN end outlet
that can be closed off is installed in one of the Combi D 6
warm air ducts (e.g. in the bathroom), a second outlet that
cannot be closed off must be installed in the warm air duct.
The warm air system is designed for each type of vehicle indi-
vidually, on a modular basis. There is an extensive accessories
program available. Diagrams showing optimum hot air system
installation suggestions in all of the common caravan and mo-
tor home models can be requested free of charge from the
Truma Service Centre.

Fuel connection

DIN EN 590-compliant diesel fuel is needed to operate the
unit.
The fuel is extracted from the vehicle fuel tank (see fuel tank
removal kit).
Only use the fuel hoses and lines included in the delivery for
installation.
Permissible fuel line length
The maximum fuel line length at the intake side is 2 m,
and 6 m at the pressure side.

Safety instructions for routing fuel lines

Always cut fuel hoses and lines to length using a hose cutter
(part no. 34020-45300) or other sharp knife. The areas that
have been cut must not be compressed and must be free of
burrs.
Fuel lines must be securely attached in order to prevent dam-
age and / or noise generation caused by vibration (recom-
mended spacing between attachment points approx. 50 cm).
Fuel lines must be protected from mechanical damage.
Route fuel lines so that vehicle twisting, engine movements
and the like do not adversely affect the stability thereof.
Protect fuel-carrying parts from heat that may affect operation
(use suitable thermal protection hose made from fibre glass
fabric with aluminium lining).
Never route or secure fuel lines immediately adjacent to the
exhaust ducts of the heater unit or the vehicle engine. If the
lines cross, maintain an adequate distance away from hot
components at all times - provide heat radiation protection
plates if necessary.
Do not leave gaps between fuel lines that are being connected
using a fuel hose. This prevents problematic bubble formation.
Correct line routing
L ≤ 50 cm
Erroneous line routing
(bubble formation)

Installing the metering pump

Always install metering pump with the pressure side (delivery
direction) sloping upwards.
Protect metering pump from heat (max. operating tempera-
ture 40 °C), therefore do not install in the vicinity of sound
mufflers and exhaust pipes.
Metering pump installation position
Permissible metering pump intake and pressure levels
Pressure level from fuel tank to metering
pump:
Intake level with depressurised fuel tank: b = max. 1000 mm
Intake level with fuel tank in which
negative pressure occurs during removal
(valve with 0.03 bar in tank cap):
Pressure level from metering pump
to heater:
c
a
b
a = max. 1500 mm
b = max. 400 mm
c = max. 2000 mm
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