Table of Contents
Advertisement
T
VR
Siemens VGD..
:
9
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.
10 Only if necessary, change the combusiton head position: see paragraph "Adjusting the combustion head".
11 the air and gas rate are now adjusted at the maximum power stage, go on with the point to point adjustement on the SV adjusting
cam as to reach the minimum output point.
12 as for the point-to-point regulation, move the gas low flame microswitch (cam III) a little lower than the maximum position (90°);
13 set the TAB thermostat to the minimum (as far as fully-modulating burners, see related paragraph) in order that the actuator moves
progressively towards the low flame position;
14 move cam III 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 V1 to increase the rate, unscrew to decrease.
15 Move again cam III 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.
16 Now adjust the pressure switches (see related par.).
SC
SV
17 If it is necessary to change the burner output in the low flame stage, move cam III: the low flame position must never match the
ignition position, that is why cam III must be set 20°- 30° more than cam II.
18 Turn the burner off; then start the burner up again. If the adjustment is not correct, repeat the previous steps.
TR
VRA
VF
33
Dungs MBC..SE
RA
Gas butterfly valve closed
Gas butterfly valve open
Advertisement
Table of Contents
