Viessmann Vitocrossal 300 Service Instructions For Contractors page 21

Air pressure switch
Combustion chamber pressure monitoring (LDW2)
A B
Fig. 11
A Reset button R
Air pressure switch 2
B
(cont.)
To monitor the combustion chamber pressure, the
switching threshold of air pressure switch 2 (LDW2) is
monitored in all operating phases (except during the
safety and stabilising time).
The air pressure switch triggers a fault shutdown of the
burner control unit under the following circumstances:
If the combustion chamber pressure is outside the
■
permissible range (> 5 mbar) in the pre-purge phase,
in control mode or in the post-purge phase after
2 attempts
The fault shutdown is indicated by fault code "F FB"
on the burner control unit display. Reset the burner
control unit by pressing reset button R.
"MatriX cylinder burner" service instructions
Rated heat- Rated heat in-
ing output put
P Q (H )
max max i
(50/30 °C) [net cv]
in kW
400
500
630
Functions
LDW2 setting value
in kW in mbar (kPa)
381
474 5 (0.5)
593
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