Viessmann Vitocrossal 200 Series Service Instructions Manual page 40

Burner control unit
Burner control unit flow chart
Description of state:
Phase Display
System start "A"
Relay test "P"
Standby "0"
Start-up "1"
"2"
"3"
"4"
"5"
Operation "6"
"7"
Shutdown "8"
Waiting "U"
"C"
Fault status "9"
"10"
"11"
"F"
40
(cont.)
Description
System start
Fan ramp-up, system start
Forced ventilation, system start
Fan ramp-up for test
Safety relay test
Disable relays BV1 and BV2.
Relays BV1 and BV2 test
Ignition relay test
Disable safety relay.
Ramp up to flue gas damper test speed.
Check flue gas damper.
Start-up meter, initialisation
Standby
Flame signal amplifier test
Gas fan and air pressure switch test
Fan ramp-up
Pre-purge
Adjusting start-up load, test WD 1
Pre-ignition
Safety time (duration depends on burner output)
Flame stabilising time
Start-up, partial load
Modulating operation
Adjust shutdown load.
After flame, test WD 2
Fan ramp-up, post-purge
Post-purge
Waiting for restart
Waiting for mains gas pressure
Forced ventilation fault
Flame tear-off
Safety shutdown
Fault shutdown
Duration
10 s
max. 20 s
20 s
max. 20 s
0.9 s
0.9 s
0.9 s
0.9 s
0.9 s
5 s
max. 60 s
0.1 s
0 ... s
max. 50 s
max. 20 s
max. 15 min
30 s
25 s
2 s
max. 4.6 s
20 s
5 s
0 to 24 h
10 s
1 s, max. 30 s
max. 20 s
10 s
min. 1 min
min. 5 min
20 s
0.5 s
0 ... s
0 ... s