Siemens LMV27.100x2 User Manual

28/219
Building Technologies Basic Documentation LMV27... CC1P7541en
4 Technical Data 17.12.2018
4.4.2 UV flame detectors QRA2 / QRA4 / QRA10
Caution!
If QRA2-UV tubes / QRA4-UV tubes / QRA10-UV tubes are used for flame
supervision on the LMV27, it must be ensured that the basic unit is permanently
connected to power (EN 298), thus enabling the LMV27 to detect flame detector
failures during startup and shutdown.
Generally, the LMV27 works with QRA flame detectors in intermittent operation.
For technical data, refer to Data Sheet N7712 covering QRA2 / QRA10 UV flame
detector!
For technical data, refer to Data Sheet N7711 covering QRA4 UV flame detector!
Operating voltage Max. 350 V peak
Required detector current in the operation
mode
Min. 30 µA
Possible detector current in the operation
mode
Max. 600 µA
Permissible length of detector line normal
cable, lay separate
Max. 6 m
Threshold values when flame is supervised by QRA:
- Start prevention (extraneous light) Intensity of flame (parameter 954) ≥18%
- Operation Intensity of flame (parameter 954) >24%
UV flame detector QRA
QRA...
Figure 7: Measuring circuit 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 X10-06/2 against earth can destroy the QRA input
 Simultaneous operation of QRA and ionization probe is not permitted!
Measuring circuit for
detector current
measurement

Siemens LMV27.100x2 Specifications

General

Brand	Siemens
Model	LMV27.100x2
Category	Controller
Language	English