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PFU 780 · Edition 02.12l
40
Parameters
4 .7 .4 Air valve opens in the case of external activation (not
during start-up)
02
00 A000 A0
t
SA2
A8
07
04
t
t
FS2
06
t
SA1
t
Z
t
FS1
03
A
10a
22e
26a
16c
18e
2c–4c
18a
14a
88
10e
26e
30a
28c
2e–4e
6a–6e
V1
1
V2
2
ϑ
1
ϑ
2
2
1
PFU 780
A
P
L1
1
2
SPS
PLC
CPE
ϑ
VR..R
VAG
TZI
2
1
UV
VAS
Parameter 30 = 0:
The air valve opens if it is activated externally by input 30e.
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 10a must be pre-
vented.
External control allows switchover between low fire and
high fire during operation.
The air valve can be activated externally via input 10a
for cooling the burner in the start-up position/standby.