Riello MB 405/2 Manuel D'entretien page 47

5 Activation, calibration and functioning
5.1 Notes on safety for the first start-up
The first start-up of the burner must be carried out
by qualified personnel, as indicated in this manual
and in compliance with the standards and regula-
tions of the laws in force.
WARNING
5.2 Adjustment of the pressure stabiliser
Calibrate the pressure adjuster by rotating the adjustment screw
using a screwdriver: by rotating clockwise there is an increase in
output pressure, by rotating anticlockwise there is a decrease in
pressure.
It is absolutely compulsory to rotate this screw at least 10 rota-
tions in the (+) direction the first time the burner is started up.
5.3 Valve adjustment
The ignition delivery (valve opening phase) should be adjusted,
after having unscrewed the cover 5) (Fig. 1, page 4), by rotating
the shaft below in the correct direction +/-; the cover itself may be
used as a tool by turning it upside down.
 1st stage delivery: partial delivery
The partial delivery (1st stage) can be regulated for up to
40% of the nominal delivery.
Rotate the ring nut 9) in the correct direction + / – to regulate
(Fig. 1, page 4).
 2nd stage delivery: main delivery
The steady state delivery is progressively reached starting
from the ignition delivery following the action of the hydraulic
brake.
5.4 Low gas pressure switch adjustment
Calibrate the gas pressure switch 8)(Fig. 1, page 4) by adjusting
the cog of the graduated scale, after having performed all other
burner adjustment with the pressure switch regulated to the start
of the scale.
Let the burner work at the required output.
Close slowly the gate valve until the pressure, measured on the
pressure switch gauge, comes down of 5 - 6 mbar with regard to
the operation value.
Rotate slowly the pressure switch handle until the operation of
the same pressure switch and the resultant burner shutdown.
Open the gate valve completely.
Activation, calibration and functioning
9
Check the correct working of the adjustment, com-
mand and safety devices.
WARNING
Only at this point will it be possible to calibrate the regulator.
When the nominal desired pressure value has been reached,
close the cover and seal the extremities of the wire leaving the
passing ring short.
the steady state delivery may be adjusted by rotating the
ring nut 6) in the appropriate direction + / – (Fig. 1, page 4)
after having loosened the unsealed screw 7).
It is nonetheless preferable to calibrate this delivery by using the
upstream pressure of the stabiliser; the considerations made in
relation to the functionality of the pressure stabiliser already stat-
ed remain valid, optimal functioning of the valves is obtained
when they are fully opened: it is therefore necessary to seek the
best compromise between the requirements of the stabiliser and
of the valves.
GB
20049136