C.I.B. UNIGAS
- M03956CR
26
Progressive burners
Once the procedure till step 8 described on paragraph “Adjusting procedure” on page 22, is accomplished, go on as follows:
9
set the low flame cam matching the high flame cam;
10 set the
TAB
thermostat to the minimum in order that the actuator moves progressively towards the low flame position;
The manual air damper control is not provided on these actuators. The adjustments must be carried out acting manually on the cams.
IBerger STA12: a key is provided to move the cams.
Siemens SQN72: a key is provided to move cams I and IV, the other cams can be moved by means of screws.
On the BERGER STA12B3.41 actuator, the manual air damper control is not provided. On the Siemens actuator the AUTO/MAN mode
is provided (see picture).
11 move the low flame cam to the minimum to move the actuator towards the low flame until the two bearings find the adjusting screw
that refers to the lower position: screw
V
to increase the rate, unscrew to decrease.
12 Move again the low flame cam towards the minimum to meet the next screw on the adjusting cam and repeat the previous step; go
on this way as to reach the desired low flame point.
13 Now adjust the pressure switches (see page 27).
14 If it is necessary to change the burner output in the low flame stage, move the low flame cam: the low flame position matches the
ignition position. As far as burners fitted with Dungs MBC gas valves, the low flame cam does not match the ignition cam position,
that is why it must be set at about 30° more than the ignition cam.
15 Turn the burner off and then start it up again. If the adjustment is not correct, repeat the previous steps.
Berger STA12B3.41 (progressive and fully modulating burners)
Siemens SQN72.4A4Axx (progressive and fully modulating burners)
For DUNGS MB-DLE / Siemens VGD gas valves
Actuator camsBerger
STA
Siemens SQN72
High flame position (set to 90°)
ST2
I (
red
)
Low flame and ignition position
ST1
III (
orange
)
Stand-by position (set to 0°)
ST0
II (
blue
)
Not used
MV
IV (
black
)
For DUNGS MBCgas valves
Actuator camsBerger
STA
Siemens SQN72
High flame position (set to 90°)
ST2
I (
red
)
Stand-by position (set to 0°)
ST0
III (
orange
)
Ignition
ST1
II (
blue
)
Low flame position
MV
IV (
black
)
MV
ST2
ST1
ST0
IV
III
II
I
AUTO/MAN
VF
SC
SV
ID
V
SV
Gas butterfly valve clo
s
ed
Gas butterfly valve open
