Siemens AGM60.4A9 - QRB Photoresistive Flame Detection

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Smart Infrastructure CC1N7544en
21.05.2021
Technical Data (cont´d)
No-load voltage at QRB1/QRB3 terminal
(X10
-
05 pin 3)
Approx. DC 5 V
Max. perm. length of QRB1/QRB3
detector
cable (laid sep
a
rately)
3 m (wire – wire 100 pF/m)

Note
A detector resistance of RF <500  is identified as a short-circuit and leads to safety
shutdown in operation as i
f the fla
me had been lost.
For this reason, before considering the use of a highly sensitive photoresistive detector
(QRB1B or QRB3S), it should be checked whether this type of flame detector is indeed
required! Increased line capacitance between QRB1/QRB3 connection and mains live
wire L has an adverse effect on the sensitivity and increases the risk of damaged flame
detectors due to overvoltage. Always run detector cables separately!
Threshold values when flame is supervised by QRB1/QRB3
Start prevention (extraneous light) with
R
QRB
Approx. 400 k
Flame intensity
≥
10
%
Operation with RQRB
Approx. 230 k
Flame intensity >16
%
Short
-
circuit detectio
n with
R
QRB
<0,5 k
0,1 1 10 100 1000
B
i
l
d
4
6
2
e
n
/
0
7
1
8
A flame detector resistance of RF <500 Ω is identified as a short-circuit and leads to
safety shutdown in operation, like in the case of loss of flame.

Note!
In the case of the QRB1/QRB3, the maximum intensity display is limited to
approximately 40% due to the system
.
Flame supervision with
QRB1/QRB3