Viessmann VITOCROSSAL 200 Service Instructions Manual page 48

Burner control unit flow chart
Burner control unit flow chart
After the controller issues a heat
demand, the following program
sequence will be run:
Phase
01 Test for heat demand
02 Checking the idle state of the air pressure switch and the
fan
03 Fan ramps up to speed (a fault shutdown will be initiated
if the air pressure switch does not report within this time
that the air pressure has reached a defined range, or if
the fan does not reach its set speed)
04 Pre-purge I
05 Pre-purge II
06 Pre-purge III
07 Ignition setting (the burner control unit will enter a fault
state if the fan does not achieve its set speed)
08 Pre-ignition
09 Safety time, start (safety time A) (enabling the safety
valves at the start of safety time A, safety time, operation
< 1 s); (no gas pressure switch monitoring)
10 Stabilising the flame in the ignition position
11 Changing to the control mode (ramps to the set speed
selected at the control unit)
12 Operation (the system will be restarted after expiry of this
time)
13 Burner run-on time
17 Post-purge
18 Restart blocking time
19 Gas shortage position
20 Standby
(a restart follows a heat demand and the system restarts
after expiry of this time)
In the case of fault shutdown from phase 09:
21 Fan run-on before lockout
48
(cont.)
Duration
1 s
1 to 30 s
1 to 30 s
5 s
1 s
30 s
1 to 30 s
2 s
2 to 10 s
20 to 60 s
1 to 30 s
max. 23:59 h
max. 30 s
1 to 60 s
0 s
max. 30 min
max. 23:59 h
5 s