PART III: OPERATION
34
6.0 ADJUSTMENTS FOR GAS OPERATION
6.1 Air flow and gas adjustment
z
startup the burner by selecting GAS by means of the switch on the burner control panel
z
Adjust the air and gas flow rates, in according to the “air/gas ratio” curvepoints setting procedure on the LMV manual,. Check con-
tinuosly, the flue gas analisys, to avoid combustion with air excess.
z
Once the butterfly valve is completely opened, acting on the pressure stabiliser of the valves group, adjust the
gas flow rate in the
high flame stage
as to meet the values requested by the boiler/utilisation:
z
If necessary, change the combusiton head positionl.
z
The air and gas flow rate are now adjusted at the maximum power stage: go on with the point to point adjustement, as to reach the
minimum output
z
Adjust the pressure switches
6.2 Multibloc MB-DLE
The multibloc unit is a compact unit consisting of two valves, gas pressure switch, pres-
sure stabilizer and gas filter.
The valve is adjusted by means of the
RP
regulator after slackening the locking screw
VB
by a number of turns. By unscrewing the regulator
RP
the valve opens, screwing the valve
closes. To set the fast opening remove cover
T
, reverse it upside down and use it as a tool
to rotate screw
VR
. Clockwise rotation reduces start flow rate, anticlockwise rotation incre-
ases it.
Do not use a screwdriver on the screw
VR
!
The pressure stabilizer is adjusted by operating the screw
VS
located under the cover
C
.
By screwing down the pressure is increased and by unscrewing it is reduced.
Note: the screw
VSB
must be removed only in case of replacemente of the coil.
Fig. 21
Fig. 22
Key
1 Electrical connection for valves
2 Operation display (optional)
3 Pressure governor closing tap
4 Start setting cap
5 Hydraulic brake and rate regulator
6 Coil
7 Test point connection G 1/8
8 Test point connection G 1/8 downstream of valve 1, on both sides
9
Output flange
10 Test point connection M4 downstream of valve 2
11 Gas flow direction
12 Test connection G 1/8 downstream of valve 1, on both sides
13 Vent nozzle pressure regulator
14 Filter (below cover)
15 Input flange
17 Pressure switch
18 Pressure switch electric connection
C
VS T(VR)
RP
VB
VSB
Fig. 20
