Unigas PN91, Manual Of Installation - Use - Maintenance

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C.I.B. UNIGAS - M039196CC
27
The nozzle supply pressure is already factory-set and must not be changed. Only if necessary, adjust the supply pressure as follows
(see related paragraph);insert a pressure gauge into the port showed on Fig. 22 and act on on the pump adjusting screw
VR (see Fig.
21) as to get the nozzle pressure at 25bar (Fluidics nozzles - see diagramd on pag. 21).
10 in order to get the maximum oil flow rate, adjust the pressure (reading its value on the PG pressure gauge): always checking the
combustion parameters, the adjustment is to be performed by means of the SV adjusting cam screw V (see picture) when the cam
has reached the high flame position.
11 To adjust the air flow rate in the high flame stage , loose the RA nut and screw VRA as to get the desired air flow rate: moving
the rod TR towards the air damper shaft, the air damper opens and consequently the air flow rate increases, moving it far from the
shaft the air damper closes and the air flow rate decreases.
Note: once the procedure is perfomed, be sure that the blocking nut RA is fasten. Do not change the position of the air damper rods.
12 If necessary, change the combusiton head position: to let the burner operate at a lower output, loose the VB screw and move pro-
gressively back the combustion head towards the MIN position, by turning clockwise the VRT ring nut. Fasten VB screw when the
adjustment is accomplished.
Attention! if it is necessary to change the head position, repeat the air and gas adjustments described above.
13 once the air and oil flow rate have been adjusted at the maximum output, go on with the point to point adjustment on the SV adju-
sting cam as to reach the minimum output point: gradually move the adjusting cam in order to adjust each of the V screws as to
describe the cam foil shape.
14 to change the SV position set the actuator on the manual mode (MAN), turn the adjusting cam SV and set again the actuator to the
AUTO mode to lock the adjusting cam;
15 act on the V screw that mathces the bearings referring to the adjusting cam position;
16 to adjust the next screw, set again the actuator mode to MAN, turn the adjusting cam and set the actuator to AUTO mode to lock
the adjusting cam on the next screw; adjust it and go on this way to adjust all the screws in order to set the cam foil shape, accor-
ding to the combustion values read.
17 Once the cam foil shape is defined, reconnect the TAB thermostat by reconnecting the wire to the terminal no.6 or setting the
RWF40 burner modulator to AUTO or the CMF switch to 3 (only for fully-modulating burner).
Fig. 22 Fig. 23
Pressure gauge port
RP
PG
V
SV
Pressure gauge port
VRA
RA
TR
VB