DURAG D-LX 200, Manual

Page: 54 / 116

Adjusting the Flame Monitor
54
D − LX 200, D − LX 720
For ideal adaptation of the Compact Flame Monitor to the local combustion
conditions, different gain characteristics can also be selected for automatic
current gain adaptation by means of (
 ) DIP switches.
The switches for the intensity (Intens.) and flame flicker frequency (Freq.) are
located on printed circuit board no.3, and the DIP switches for selecting the
gain characteristic are located on printed circuit board no.2.
The designations of the printed circuit boards can be seen in Figure 6.1 .
Figure 6.1: Printed circuit board numbering
For many applications it should be possible to use the D
− LX 200, D − LX 720
for reliable flame monitoring either with the factory settings, or by adjusting
only thresholds.
6.1 Adjusting the thresholds
In addition to the usual threshold for the flame intensity (Figure 6.3), the
D
− LX 200, D − LX 720 also offers the option of using the different flicker
frequencies of the flame and the background radiation (Figure 6.4) to decide
between Flame OFF and Flame ON.
The settings of both thresholds allow the commissioning engineer/operator of
the furnace plant to decide which flame signal (Intens.) and which flame flicker
frequency (Freq.) will be used to generate the Flame ON or OFF signal.
The thresholds are set by means of the rotary switches on printed circuit board
no. 3. As the thresholds can be set differently for
Range A
and
Range B
(see
6.3 Range selection from page 59), there are separate rotary switches for both
ranges (Figure 6.2). The switches for Range B only need to be operated if this
range is used (see chapter 6.3 from page 59).
The thresholds can be set in 16 positions (0…9, A…F). Position 0 corresponds
to the lowest setting, F to the highest setting. The relevant threshold values
can be found in Figure 6.3: Setting Intensity and Figure 6.4: Flicker frequency
setting [Hz] of the flame .
The rotary switches do not have a stop. They can be turned from switch
position F to switch position 0.
When the device is delivered, all rotary switches are set to position 0 (zero)
(default setting).
No. 1
No. 2
No. 3
(Front panel)
No. 4