Siemens AGM60.4A9 - QRA UV Flame Detector Supervision

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Smart Infrastructure CC1N7544en
21.05.2021
Technical Data (cont´d)
Warning!
If UV flame detectors QRA2 / QRA4 / QRA10 are used for flame supervision with
the LMV36, it must be ensured that the LMV36 is permanently connected to
power (conforming to DIN EN 298), thus enabling the LMV36 to detect flame
detector failures during startup and shutdown. Generally, the system works
with QRA flame detectors in intermittent operation. Technical Data refer to
Data Sheet N7712 covering UV flame detectors QRA2 / QRA10! Technical Data
refer to Data Sheet N7711 covering UV flame detectors QRA4
!
Operat
ing volta
ge
Max. 350 V peak
Required detector current in operation Min. 30 µA
When the more sensitive flame
supervision is activated, the required
detector current is halved (refer to chapter
Flame detection sensitivity in the Basic
Documentation P7544).
Possible detector current in operati
on
Max. 6
00 µA
Permissible length of flame detector
cable, normal cable (laid separately)
Max. 6 m
Threshold values when flame is supervised by QRA
:
-
Start prevention (extraneous light)
Flame intensity (parameter 954)
≥
18 %
-
Operation
Flame inten
sity (par
ameter 954) >24 %
UV flame detector QRA
QRA...
Legend
A Incidence of light
C Electrolytic capacitor 100...470 µF; DC 10...25 V
M Microammeter Ri max. 5000 
Warning!
 Input QRA... is not short-circuit-proof!
Short-circuits of X10-06 pin 2 against earth can destroy the QRA input

Simultaneous operation of QRA
and ionization probe is n
ot permitted!
Flame supervision with
QRA2
/ QRA4
/ QRA10
Measuring circuit for
detector current
meas
u
rement