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Technical Data (cont´d)
Flame supervision with
QRB1/QRB3
24/30
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No-load voltage at QRB1/QRB3 terminal
(X10-05 pin 3)
Max. perm. length of QRB1/QRB3
detector cable (laid separately)
Note
A detector resistance of RF <500 is identified as a short-circuit and leads to safety
shutdown in operation as if the flame 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
Operation with R
QRB
Short-circuit detection with R
0,1
1
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.
Approx. DC 5 V
3 m (wire – wire 100 pF/m)
Approx. 400 k
Flame intensity ≥10%
Approx. 230 k
Flame intensity >16%
<0,5 k
QRB
10
100
1000
CC1N7544en
21.05.2021
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