Viessmann VITODENS 200-W Service Instructions Manual page 103

Electronic combustion controller
Air factor λ – CO /O content
2 2
Air factor O content
2
λ
(%)
1.24 4.4
1.27 4.9
1.30 5.3
1.34 5.7
1.37 6.1
1.40 6.5
1.44 6.9
To achieve an optimum combustion con-
trol, the system regularly carries out an
automatic self-calibration; also after a
power failure (shutdown). For this, the
combustion is briefly regulated to max.
ionisation current (equals air factor λ=1).
The automatic calibration is carried out
shortly after the burner start and lasts
approx. 5 s. During calibration, higher
than normal CO emissions may occur
briefly.
(cont.)
CO content (%) CO
2
for natural gas for natural gas
E LL
9.2 9.1
9.0 8.9
8.7 8.6
8.5 8.4
8.3 8.2
8.1 8.0
7.8 7.7
Function description
content (%) CO content
2 2
(%) for LPG P
10.9
10.6
10.3
10.0
9.8
9.6
9.3
103