BCU 480 · Edition 06.07
40
Air valve opens in the case of external activation (not
5 .7 .4
during start-up)
t
SA2
A8
07
04
t
t
FS2
06
88
A
18-19
23
26
28-29
12
9
V1
1
14
V2
4
5
2
7
24 2
21
16-17
1
2
ϑ
1
ϑ
2
VR..R
VAG
UV
BCU 480..L
A
P
L1
1
2
SPS
PLC
CPE
VAS 1
ϑ
Parameter 30 = 0: The air valve opens if it is activated exter-
nally via input 23.
Parameter 31 = 0: The air valve remains closed during start-
up even if it is activated externally.
These settings are required on burners on which the gas/air
ratio is controlled via a pneumatic link and which also need
to be started at low fire, e.g. on two-stage-controlled burners.
In this case, activation of the air valve during burner start via
input 23 must be prevented.
External control allows switchover between low fire and high
fire during operation.
Parameters > Air valve control on BCU . .L