Flame Detectors; Ionization Probe - Siemens LMV27.100x2 Basic Documentation

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Building Technologies

4.4 Flame detectors

4.4.1 Ionization probe

No-load voltage at ION terminal
(X10–05 pin 2)
Caution!
The ionization probe must be protected against electric shock hazard!
Short-circuit current
Required detector current
Possible detector current
Max. perm. length of detector cable
(laid separately)
Warning!
Simultaneous operation of QRA and ionization probe is not permitted!
Note
The higher the detector cable's capacitance (cable length), the more voltage at the
ionization probe, and thus the detector current, drops. Long cable lengths plus very
highly resistive flames might necessitate low-capacitance detector cables (e.g. ignition
cable). In spite of technical measures taken in the circuitry aimed at compensating
potential adverse effects of the ignition spark on the ionization current, it must be
made certain that the minimum detector current required will already be reached
during the ignition phase. If this is not the case, the connections on the primary side of
the ignition transformer must be changed and / or the electrodes relocated.
Basic Documentation LMV27...
4 Technical Data
Approx. U
Mains
Max. AC 1 mA
Min. DC 2.3 µA, flame display approx.
30%
Max. DC 12...30 µA, flame display
approx. 100 %
3 m (wire–ground 100 pF/m)
CC1P7541en
17.12.2018