DURAG D-LX 200, Руководство пользователя

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Installation, Commissioning
Over short distances (< 5m) the lines are unsusceptible to interference and do
not need to be protected.
The single wires can be defined according to the system-specific
requirements. The cross-section for the 24 V DC supply line must be large
enough to ensure that
R = 10

per wire is not exceeded. The D − LX 200,
D − LX 720 flame monitor will then still operate reliably at
V 20 ) 10 2 mA 200 ( V 24
    
.
The D − LX 200, D − LX 720 has an electrically isolated design. There is no
connection between the 24V DC supply voltage and the internal voltage of the
flame monitor. If faults occur after installation, the cause can be a ripple
voltage between the 0V potential of the supply and the internal operating
voltage.
This can be remedied with a capacitive coupling C1= approx. 100nF
or
by
eliminating the electrical isolation with a bridge B1.
D-LX 200
D-LX 720
1
2
FE
B1 C1
LX
200-
12-
002
Kessel Versorgung
Supply
Boiler
Figure 5.5: Elimination of the potential isolation
5.3.5 Installation, purge air supply
The purge air connection of the Compact Flame Monitor is responsible for
keeping the sighting tube and the optics free of particles from the combustion
chamber. A current of air, strong enough to blow away heavy particles, must
therefore be aimed toward the combustion chamber. In applications with low
particle levels, like gas burners, air velocities of v= 1 m/s will sufficiently purge
the air in a 1¼" sighting tube (air consumption approx. 3m³/h). Applications
with higher levels, like coal-fired burners, require more purge air (air velocity v
= 3 m/s). These velocities for the purge air in the sighting tube can only be a
guide value and must be adapted to the specific system. A 1/2" screw
connection with female thread provides the purge air connection on the flame
monitor.
The flame monitor should be routinely checked to ensure that the optics are
clean and that the monitor is firmly mounted in the front part.
If flame monitors must be mounted to sighting tubes with high temperature
exposure, the purge air also serves for cooling. In such cases it is advisable to
use thermal insulator D-ZS 117 I (see page 26) between flame monitor and
sighting tube. However, you must always ensure that the Compact Flame
Monitor does not exceed the maximum operating temperature of +85°C.
If there is an over-pressure on the sighting tube of the Compact Flame
Monitor, we recommend installing ball-type valve D-ZS 133 I (see page 26)
between flame monitor and sighting tube. If the optical system is soiled,
cleaning can then be safely carried out after closing the ball-type valve.
48
D − LX 200, D − LX 720