Baxi MB DLE 405 B01 Instrucciones De Instalación, Uso Y Mantenimiento página 7

ENGLISH
GAS TRAIN ASSEMBLY
The gas trains must be installed on the left side of the
burner: in case of assembly on the right side, it is nec-
essary to remove the pressure test point on the other
side 2)(Fig. 1).
It can be necessary to insert an adapter between the
gas train and the burner, if the gas train diameters are
different from the burner diameter.
The connection between the gas supply line and the
gas train is made by using the flange 1)(Fig. 1), sup-
plied with the gas train and by fixing it to the assembly
with nuts 3)(Fig. 1).
PRESSURE LOSSES
The gas train pressure loss Dp is provided from the
diagram; the scales of the volumetric output
valid respectively for:
a = air; n = natural gas (G20); p = propane (G30); 
c = city gas (G140), only for applications not covered
by the Gas Appliances Regulation (2016/426/EU).
The value, provided from the diagram, can be differ-
ent according to the pressure stabilizer adjustment.
The minimum necessary pressure in the network can
be obtained by adding the pressure of the diagram to
the burner pressure losses (see the burner technical
instruction) and the back pressure of the combustion
chamber (see the technical instruction of the heat
generator).
FILTER MAINTENANCE
Replace the filter at least one time in the year by
removing the 4 screws of one of the lateral small
cover with the notice FILTER.
PRESSURE STABILIZER ADJUSTMENT
Reach the adjusting screw by rotating the small cover
4)(Fig. 1).
For the burner's first start-up, this screw must be
turned at least 10 turns in the (+) direction. Only then
can the regulator be set.
With the clockwise rotation, there is an output pres-
sure increase; with the counter-clockwise there is a
pressure reduction.
VALVE ADJUSTMENTS
The firing delivery (fast valve opening phase) must be
regulated, once cap 5)(Fig. 1) has been unscrewed,
by turning the short shaft underneath the appropriate
way (+/-). The actual cap itself can be turned over
and used as a tool.
Delivery for steady-state operation is reached pro-
gressively, starting with the start-up delivery, subse-
quent to the action of the hydraulic brake. 
Steady-state delivery can be adjusted by turning ring
6)(Fig. 1) the appropriate way (+/-), loosening the
unsealed screw 7)(Fig. 1) first.
Nonetheless, it is best to set said delivery by altering
pressure downline from the stabilizer. Optimal valve
operation is achieved with them fully open, though the
2902156
tips given earlier for the pressure stabilizer's opera-
tion still apply: consequently, you will need to deter-
mine what the best compromise is between the
stabilizer's demands and the valves.
LOW GAS PRESSURE SWITCH ADJUSTMENT
Adjust the low gas pressure switch 8)(Fig. 1), after
carrying out all the other adjustments of the burner
with the gas pressure switch adjusted at the begin-
ning of the scale.
Run the burner at maximum output.
Close slowly the gate valve until the pressure, meas-
ured on the gas pressure switch gauge, comes down
of 5 - 6 mbar with regard to the working value.
Rotate slowly the gas pressure switch handle until the
V °
are
operation of the same gas pressure switch and the
resultant burner shut-down. Open completely the
gate valve.
VPS 504 VALVE LEAK DETECTION CONTROL
DEVICE (if present)
The valve leak detection control device is compulsory
(pr EN 676) on the gas supply trains of burners with
rated maximum output greater than 1200 kW. In
some countries, it is also required for lower outputs.
This leak detection control device operates by creat-
ing an overpressure between the two valves of about
20 mbar compared to the pressure upline. 
Testing time depends on the volume to be pressur-
ized as well as the pressure upline and varies from
between 10 and 26 seconds.
The yellow pilot lamp lighting up confirms the positive
outcome of the test, while a negative outcome, with
the resulting lockout, is reported by the red pilot lamp
lighting. Lockout continues for as long as the leak
detection control device remains live.
A functional test can be carried out by unscrewing the
screw of pressure test point p a on the unit before
checking: the leak detection control device must lock
out.
The fuse can be reached by using a screwdriver to
remove the cap near the electrical connection sock-
ets. A spare fuse is housed in the upper part of the
leak detection control device under the plug.
Correct assembly entails removing the two plugs 1)
(Fig. 3). Position it making sure that both orifices fea-
ture the O-ring supplied with the leak detection con-
trol device, and secure it in place with the four screws
2)(Fig. 3). Follow the instructions supplied with the
burner to make electrical connections.
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