Viessmann Vitocrossal 200 CM2 400 Service Instructions Manual page 52

Flow Diagram
Burner Control Unit Flow Diagram
State description:
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 states "9"
"10"
"11"
"F"
52
Vitocrossal 200, CM2 400, 500, 620 and 620 TX Service
(continued)
Description
System start
Fan ramp-up, system start
Forced ventilation, system start
Fan ramp-up for valve test
Safety relay test
Relay/valve test BV1
Test time BV1
Relay/valve test BV2
Test time BV2
Start-up meter, initialization
Standby
Flame signal amplifier, test
Gas fan, air pressure switch and boiler water
temperature sensor test
Fan ramp-up
Pre-purge
Adjusting start-up load, test WD1
Pre-ignition
Ignition safety time
Flame detection safety time
Flame stabilizing time
Start-up partial load
Modulating operation
Adjusting shutdown load
Reheat, test WD2
Fan ramp-up, post-purge
Post-purge
Waiting for restart
Waiting mains, gas pressure
Forced ventilation fault
Flame tear-off
Safety shutdown
Fault shutdown
Duration
10 seconds
max. 20 seconds
20 seconds
max. 20 seconds
0.9 second
2 seconds
1.1 seconds
2 seconds
1.1 seconds
0.1 second
0 ... seconds
max. 50 seconds
max. 20 seconds
max. 20 seconds
10 seconds
1.9 seconds
2 seconds
2.3 seconds
max. 0.51 second
15 seconds
20 seconds
0 to 24 hours
0.1 seconds
min. 10 seconds
max. 60 seconds
max. 20 seconds
10 seconds
5 minutes
5 minutes
20 seconds
0 ... seconds
0 ... seconds
0 ... seconds