Checking The Settings Of The Air Damper Servomotor - Viessmann Vitoflame 300 VHG III Service Instructions Manual

Commissioning, inspection, maintenance
Checking the oil pressure and vacuum , adjusting...

Checking the settings of the air damper servomotor

The air damper servomotor is factory-set and must only be adjusted in exceptional cases. Exceptions are the
replacement of the air damper servomotor, soot build-up and the altitude above sea level of the installation
site. The CO value must only be adjusted by regulating the oil pressure.
2
Z
ST2
BV
SL
ST1
Fig. 5
The burner is equipped with an air damper servomotor
with adjustable switching cams for the positioning of
the air damper and the solenoid valve control.
During a controlled shutdown, the burner air damper
moves into the "closed" position. This reduces the
cool-down losses.
8
90 30 0
90 60 30 0
90 60 30 0
90 60 30 0
90 60 30 0
(cont.)
08. Test to check the actual emission values after
adjusting the oil pressure.
09. Switch system OFF at mains isolator and safe-
guard against unauthorised reconnection.
10. Undo the pressure and vacuum gauges.
11. Check the plug seal rings for damage and replace
if necessary.
Insert plugs "P" and "V"
A
12. Start the burner and check the plugs for leaks.
The switching cams are located under the cover of the
air damper servomotor. A scale ring is located adjacent
to each switching cam, where the selected angle of the
air damper can be checked.
The switching cams have the following function:
Z Air damper closed (0
Never alter the setting of Z.
SL Ignition air setting
ST1 Air damper stage 1
ST2 Air damper position stage 2
BV Solenoid valve stage 2
The switching cams for ignition air stage 1 and 2 are
set at the factory. Factory settings, see chapter "Stand-
ard values for burner adjustment".
The switching cams are adjusted by means of slotted
screws in the cams. When doing this observe the
A
following:
■ The ignition air setting cannot be turned beyond the
setting of stage 1 (turning further is blocked by
cams).
■ After setting, match the start air setting to stage 1;
always adjust the start air setting approx. 1-5
stage 1.
.
B
)
°
below
°