Qrb1/Qrb3/ Qrb4 - Siemens LME71 Series Basic Documentation

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4.12.3 QRB1/QRB3/ QRB4

No-load voltage at the QRB4 terminal
(X10–05, terminal 3)
Required detector current in operation
Possible detector current in operation
Perm. length of detector cable
(normal cable, laid separately) ¹)
¹)
Multicore cable not permitted
Notes

Increasing line capacitance between QRB connection and "L" mains phase impairs
sensitivity. Always run detector cables separately

Before using a highly sensitive QRB1B and QRB3S, check carefully whether they
are necessary

QRB4 cable connection!
Blue QRB4 cable to terminal X10-05 pin 4.
Black QRB4 cable to terminal X10-05 pin 3.
Otherwise the QRB4 will not function.
Check the flame intensity via the AZL2 or the internal LED display (flame current, FL2).
The maximum possible QRB flame current is limited to approx. 60 µA for system-
specific reasons. The maximum display intensity (parameter 954 in the AZL2 or via
internal LED display FL2) corresponds to 100%.
Threshold values when flame is supervised by QRB

Start prevention (extraneous light)
Intensity
Flame current
Operation, minimum required flame signal
Intensity
Flame current

Signaling good/bad flame (LED starts flashing green during operation)
Intensity
Flame current

Typical flame signal during operation
Intensity

Maximum flame signal during operation
Intensity
Flame current
Parameters Function
954 Flame intensity
The values specified in the table only apply under the following ambient conditions and
may vary under other conditions:

Mains voltage 230 V AC

Ambient temperature 23°C
Basic Documentation LME7...
4 Technical data
Approx. 5 V DC
Min. 20 µA (display intensity approx.
35%)
Max. 60 µA (display intensity 100%)
Max. 3 m (core-core 100 pF/m)
AZL2 (parameter 954) or FL2 >10%
>10 µA
AZL2 (parameter 954) or FL2 >35%
Approx. 20 µA
AZL2 (parameter 954) or FL2 approx. 50%
Approx. 30 µA
AZL2 (parameter 954) or FL2 ≥60%
AZL2 (parameter 954) or FL2 ≤100%
Approx. 60 µA
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CC1P7105enr
24.07.2020