User Manual

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Building Technologies CC1N7546en
13.04.2018
Technical Data (cont´d)
Warning!
If UV flame detectors QRA2… / QRA4... / QRA10... are used for flame
supervision with the LMV37.4, it must be ensured that the LMV37.4 is
permanently connected to power (conforming to EN 298), thus enabling the
LMV37.4 to detect flame detector failures during startup and shutdown.
Generally, the LMV37.4 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...!
Operating voltage 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 (see chapter
Flame detection sensitivity).
Possible detector current in operation Max. 600 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 intensity (parameter 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 ς
Warning!
∂ Input QRA... is not short-circuit-proof!
Short-circuits of X10-06/2 against earth can destroy the QRA... input
∂ Simultaneous operation of QRA... and ionization probe is not permitted!
Flame supervision with
QRA2... / QRA4... /
QRA10...
Measuring circuit for
detector current
measurement