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PFU 780 · Edition 02.12l
69
Glossary
12 .5 Safety time during operation t
SB
tSB
t
04
04
30e
10e
28c
16c
26a
18e
L1
V1
V2
88
2e–4e
2c–4c
ϑ
If the flame fails during operation, the valve outputs
are disconnected within the safety time t
SB
.The default
safety time during operation t
SB
in accordance with
EN 298 is 1 second. In accordance with EN 746-2, the
safety time of the installation during operation (in-
cluding closing time of the valves) may not exceed 3
seconds (see “Project planning information”). Note the
requirements of the Standards!
12 .6 Flame signal
If a flame is detected, the flame detector will supply a
flame signal.
12 .7 Fault lock-out
In the event of a fault lock-out, all valves and the igni-
tion transformer are disconnected from the electrical
power supply, and a fault is signalled. Resetting must
take place manually following a fault lock-out.
12 .8 Safety interlocks (Limits)
The limiters in the safety interlock (linking of all the rel-
evant safety control and switching equipment for the
use of the application, e.g. safety temperature limiter,
minimum/maximum gas pressure) must isolate input
( ) from the voltage supply.
12 .9 Pilot gas valve V1
The start fuel flow rate for the pilot burner is released by
pilot gas valve V1. It opens when the safety time on start-
up t
SA1
starts to elapse. It remains open until the burner is
switched off again by a normal shut-down or fault lock-out.
12 .10 Main gas valve V2
The start fuel flow rate for the main burner is released
by main gas valve V2. It opens when the safety time on
start-up t
SA2
starts to elapse. It remains open until the
burner is switched off again by a normal shut-down or
fault lock-out.
N (L2)
22e
16c
N
26e
30a
32c
230 V
F1
18e
2a
4a
a
2e
4e
s
2c
4c
m
sk1
V2
V1
L1 (L1)
max. 1 A, 24 V
v2
v1
6a
6e
n
c1
24 V
0 V
c2
10c
12c
10a
12a
30e
22a
P
DI
A
2
1
1
N
2
28c
26a
ϑ
1
ϑ
2
14a
14e
10e
12e
24c
20c
18a
l
20c
18a
N
26a
26a
N
28c
28c
18a
Z
I
UVS
1
2
3
24c
L
N
M
V2
V1
C
µC
SK
A
S
PFU 780