PART III: OPERATION
27
Air and Gas Flow Rate Settings by means of Berger STM30../Siemens SQM40.. actuator
check the fan motor rotation.
5
Only for burners provided with
Multibloc MB-DLE gas valves:
before starting the burner up, set the slow opening. To set the slow
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 increases it. Do not use a screwdriver on the screw
VR
!
Note:
the screw
VSB
must be removed only in case of replacemente of the coil.
6
Before starting the burner up, drive the high flame actuator microswitch matching the low flame one (in order to let the burner ope-
rates at the lowest output) to safely achieve the high flame stage.
7
Start the burner up by means of the thermostat series and wait until the pre-purge time comes to an end and that the burner starts
up;
8
drive the burner to high flame stage, by means fo the thermostat
TAB
.
9
Then move progressively the microswitch to higher values until it reaches the high flame position; always check the combustion
values and eventually adjusting the gas by means of the valves group stabiliser.
10 go on adjusting air and gas flow rates: check, continuosly, the flue gas analisys, as to avoid combustion with little air; dose the air
according to the gas flow rate change following the steps quoted below;
SQM40.265 CSV Actuator cams
11 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:
- Siemens VGD valves group:
remove cap
T
and act on the
VR
adjusting screw to increase or decrease the pressure and conse-
quently the gas rate; screwind
VR
the rate increases, unscrewing it decreases (see next figure).
12 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.
MAN-AUTO
(RD) I
High flame
(BU) II
Stand-by
(OG) III
Low flame - gas
(YE) IV
Low flame - oil
(BK) V
Ignition - oil
(GN) VI
Ignition - gas
VR
T
Siemens VGD..