Technical information
IFD 244 · Edition 03.08
32
Glossary
Flame simulation/Flame simulation delay 12.5
time t
LV
t
1
3
5
9
4
L1
t
W
t
LV
7–8
ϑ
0101
Flame simulation is an incorrect flame signal. If flame simu-
lation is detected during start-up, the flame simulation delay
time tLV (max. 25 s) starts to elapse. If the flame simulation
is discontinued during the flame simulation delay time t
LV
,
start-up can be initiated or operation continued. Otherwise,
a fault lock-out occurs.
Safety time during operation t12.6
SB
t
SB
t
1
3
5
9
4
L1
04 04
88
7–8
ϑ
If the flame fails during operation, the valves are closed within
the safety time t
SB
.
The default safety time during operation t
SB
is 1 second. In
accordance with EN 746-2, the safety time of the installation
during operation (including closing time of the valves) may not
exceed 3 seconds (see “Project planning information”). Note
the requirements of the Standards!
Flame signal12.7
If a flame is detected, the flame detector will supply a flame
signal. A DC ammeter is installed in the flame signal cable in
order to measure the flame signal intensity. The amperage
is usually between 1 µA and 30 µA. Voltage surges, short-
circuits or leak currents in the flame signal cable produce an
alternating current signal and are recorded as a fault with
both types of monitoring.
Fault lock-out12.8
In the event of a fault lock-out, all valves are closed and a
fault signalled. Resetting must take place manually following
a fault lock-out.
Safety interlocks (Limits)12.9
The limiters in the safety interlock (linking of all the relevant
safety control and switching equipment for the use of the ap-
plication, for example S
TB
(safety temperature limiter), Gas
min
,
Gas
max
...) must isolate input 3 from the voltage supply.
Gas valve V112.10
The gas valve V1 is opened at the start of the safety time on
start-up t
SA
. It remains open in the event of a fault, or until the
burner is switched off.
Continuous operation12.11
The gas burner has been running for longer than 24 hours
and was not switched off during that time.