Siemens LOK16 Series - Flame supervision; Detector current measurement

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Building Technologies Division CC1N7785en
20.11.2017
Technical data (cont´d)
LOK16... LGK16...
RAR9...
QRA5x.C...
QRA5x.E...
QRA5x.D...
QRA5x.G...
Ionization probe
Operating voltage (Terminal 23 or 24) <DC 1 V
±10%
AC 280 V ¹)
±10%
AC 280 V ¹)
±10%
AC 245 V ¹)
±10%
Minimum detector current required DC 6 µA DC 35 µA DC 120 µA DC 12 µA
Maximum possible detector current DC 38 µA DC 50 µA DC 270 µA DC 100 µA
Short-circuit current --- --- --- Approx. AC 300 µA
Maximum length of detector cable (laid separately) 100 m ²) ²) 60 m ³)
1) AC voltage, measured with no detector current at AC 230 V mains voltage. Internal resistance of measuring instrument 10 M. The
shutter of the flame detector QRA53.../QRA55... is powered by mains voltage
2)  Detector cable laid in a minimum distance of 5 cm from other mains carrying cable:
- As a multiple cable
- With 5 single wires
Max. 50 m
Max. 70 m
 With a shielded 3-core control cable to terminals 3, 4 and 5 of the flame detector QRA53.../QRA55... and
standard mains cable to terminals 1 and 2
Max. 15 m
 With 2 shielded single-core coaxial cables (45 pF/m, e.g. RG 62) to terminals 3 and 4 of the flame detector
QRA53.../QRA55... and standard mains cable to terminals 1, 2 and 5
Max. 60 m
 If possible, shielding should be earthed at both ends
3) Longer cable distances are permitted when connecting low-capacitance detector cables to terminal 24 of the burner control
(especially against earthed wires!)
Detector current measurement
The measuring device must be connected between the detector and terminal 22 (+pole
to terminal 22).
With RAR9...
22
24
DC 6...38 µA
+
RAR9...
+
A
7785v02/1008
Notice!
Use the KF8832 measuring device (not suited for continuous operation).
There is no self-checking while measurements are made.
The KF8832 is not required when using the QRA5x.D.../QRA5x.G...
With QRA5x.C.../QRA5x.E... With QRA5x.D.../QRA5x.G...
22
DC 35...50 µA
+
A
+
470 µF/25 V
7785v04/1008
22
DC 120...270 µA
+
A
+
470 µF/25 V
7785v01/1008
Flame supervision
Measuring circuit for
detector current
measurement
LOK16.../RAR9...
LGK16.../QRA53.../
QRA55...