Viessmann VG III - Checking adjustment of air damper actuator

9
Initial start-up, inspection and maintenance
Further details regarding the individual steps (cont.)
Checking adjustment of air damper actuator
The burner is equipped with an air
damper actuator motor with
adjustable switching cams for setting
the air damper position and for
switching the solenoid valves.
During a regular shutdown, the
burner air damper will drive into the
"closed" position. This reduces
cooldown losses.
The switching cams are located
below the air damper actuator motor
cover. A scaling ring is located
adjacent to each switching cam,
which enables the set angle of the air
damper to be checked.
The switching cams have the
following function:
STĂ0 Air damper closed (0º)
Never alter the STĂ0 setting.
STĂ1 Air damper setting stageĂ1
STĂ2 Air damper setting stageĂ2
MV Solenoid valve stageĂ2
The switching cams for stageĂ1 and 2
are set up at the factory.
For factory settings, see the
following table.
The switching cams are adjusted via
the slotted screws on the cams.
Rated output range
from kW
to kW
90
100
125
140
150
165
190
210
Boiler output kW 90 100 125 140 150 165 190 210
Standard values for
switching cams
STĂ1Ă º 18 20 19 21 22 24 20 22
STĂ2Ă º 70 70 70 70 70 70 70 70
MV º 30 30 30 30 30 30 30 30
5692Ă534ĂGB