Page
6 D-LX
100
To guarantee the best, most selective flame monitoring, one must determine the correct position of the
scanner, since the flame must be visible to the flame scanner at all times, regardless of the load range
of the burner. The 6
°
angle of view should always be oriented toward the root of the flame, that is, the
bottom third of the flame. The D-LX 100 is mounted onto a sighting tube with a 1¼” pipe (male thread
connection). A D-ZS 033-I adjustable ball joint flange is available to more easily align the scanner
with the flame.
The flame scanner’s purge air connection is responsible for keeping the sighting tube and optics free
of particles from the combustion chamber. A current of air, strong enough to blow away heavier
particles, must therefore be aimed toward the combustion chamber. In applications with low particle
levels, like gas burners, a purge air velocity of v = 3 ft/s (1 m/s) in a 1¼” sighting tube will sufficiently
purge the scanner (air consumption 100 ft
3
/h [3m
3
/h]). Those with higher levels, like coal-fired
burners, require more purge air (v = 10 ft/s [3 m/s]). These velocities for the purge air in the sighting
tube are only guidelines. Changes on a site-specific basis are certainly permissible. The scanner is
equipped with ½” female pipe connection for the purge air.
The flame scanner should be routinely checked to ensure that the optics are clean and that the
scanner is firmly mounted to the sighting tube.
For optimal alignment of the flame scanner, the D-LX 100 uses a 4-20 mA (or 0-20 mA, if desired)
current output which displays the flame intensity.
Note:
the current output leads are not galvanically
separated from the internal voltage supply. To avoid having faults attributed to the flame scanner,
these leads may need to be shielded. As a rule, however, shielding is not required for cable lengths
below 15 ft (5 m).
For high availability in the system, the power supply equipment and the flame scanner must be
properly timed (power supply and maximum time for outages). In order to avoid possible interference
in the grounded lead from any transient currents (e.g., current from an ignition device against ground
potential), DURAG D-ZS 117-I insulators may be used between the sighting tube and the flame
scanner. One must make certain, however, that the pipe or hose conduit for the scanner’s purge air
connection is also made of non-conducting material.
!
When connecting the flame scanner, all local regulations must be observed.
The flame scanner is equipped with a safety screw to ensure that the scanner
is firmly in place. Always be certain that the flame scanner has been mounted
properly.
6.1. Start-Up
Once mounted and connected according to the drawings and diagrams in this manual, the D-LX 100
All-In-One Flame Scanner is immediately ready for operation once power is supplied.
7. Programming the Flame Scanner
The flame scanner is equipped with a push button switch for adjusting the flame recognition threshold
of the flame relay. This threshold may be set to one of ten levels. The scanner is also equipped with
a hook switch for adjusting the amplification of the photo current to one of two different levels. This
amplification feature is unnecessary for the D-LX 100 UL, and is therefore not found on that scanner.
The push button switch is accessible after removing the cover plate. The hook switch is still obscured
by the housing even if the cover plate has been removed, since it is only intended to be switched
under special circumstances for dampening very high flame signals.