Riello RL 190/M Instrucciones De Instalación, Uso Y Mantenimiento página 14

D1229
1 - Servomotor
2 - Adjustable profile cam
3 - Adjustment screws for cam profile
4 - Adjustment fixing screws
5 - Adjustment screws for cam profile
(A)
(B)
3 - INTERMEDIATE OUTPUT
The setting of the minimum and maximum pres-
sure automatically determines the pressure val-
ues and therefore those of the intermediate
outputs.
Combustion setting
During setting of the minimum and maximum
pressure it is sufficient to regulate an acceptable
excess of combustion air judged visibly solely.
Only after having set the minimum and maxi-
mum pressure, carry out an accurate setting of
the combustion on different positions of modula-
tion operating solely on the setting of the air
delivery by means of the screws 3)(A) of the
cam.
Press the switch 2)(C)p.10 "output increase" a
little so that the servomotor turns by about 15°.
Adjust the screws until optimal combustion is
obtained.
Proceed in the same way with the other screws.
Take care that the cam profile variation is pro-
gressive.
Once the setting of the combustion is complete,
lock the screws 4)(A) and check ignition once
again: noise emission at this stage must be
identical to the following stage of operation. If
you notice any sign of pulsations, reduce the
ignition stage delivery.
N.B.: The servomor follows the adjustment of
cam III only when the cam angle is reduced. If it
is necessary to increase the cam angle, first
increase the servomotor angle with the key "out-
put increase", then increase the III cam angle,
and finally bring the servomotor back to the MIN
output position with the key "output decrease".
In order to adjust cam III, especially for fine
movements, key 10)(B) , held by a magnet
under the servomotor, can be used.
Warning
•
The proper setting of the eccentric 7)(A)pag.
11 is possible when its operation field follows
the servomotor operation field (20° ÷ 130°): so,
that every variation of the servomotor position
corresponds to a pressure variation.
•
Do not let the piston beat repeatedly: the stop
ring 4)(A)pag. 11 determines the max. stroke.
•
When the setting has been carried out and
the burner switched off, verify manually, after
having released the servomotor pushing and
moving the button 3)(B) towards the right, that
no slow-down occurs.
•
If you wish to check the delivery capacity of
the nozzle, open the burner, attach the nozzle,
simulate the start-up and then proceed with
weighing of the maximum and minimum pres-
sures of the fuel.
•
In the minimum modulation position, in order
to facilitate the firing of the flame, adjust the
pressure on the nozzle return to a value ranging
between 3 and 6 mbar with an air pressure to
the head, measured at the socket 12)(A)p.3  5
D889
mbar.
•
If, during adjustment of the maximum output,
flame instability or pressure fluctuations on the
return arise, then it is necessary to decrease
this pressure until such problems have been
eliminated.
•
During adjustment of the intermediate outputs
it is advisable to adjust the air in certain posi-
tions so that the bearing which slides over the
variable profile foil of the cam is found directly
by the side of one of the screws 3)(A); this is
necessary in order that the adjustment carried
out on a screw alters the contiguous adjust-
ments as little as possible.
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