Dungs DGAI. 69F Manuale - Pagina 3

Sfoglia online o scarica il pdf Manuale per Camino da interno Dungs DGAI. 69F. Dungs DGAI. 69F 4. Automatic gas burner control for gas burners without fan, with intermittent ignition burner and exhaust gas monitoring

Functional and program sequence

Startup after regulator circuit, with flame formation
AWZ
STABZ
Switch-off via exhaust gas temperature followed by startup
Exhaust gas
15 min
delay period
Restart after flame failure during operation
SZB
Startup after regulator circuit, without flame formation
SZA
STVZ
Program sequence periods
Startup delay period (AWZ)
Stabilising period (STABZ)
Safety period startup (SZA)
Safety period operation (SZB)
Fault interlocking period (STVZ)
Exhaust gas delay periodapprox. 15 min.
The SZB is < 3 s immediately after
main valve release and reduces to
< 1 s after an operation of approx. 30 s.

Ionisation flame monitor

An ionisation electrode acts as a probe
in the flame, the burner nozzle normal-
ly acts as ground.
Ensure that there is proper flame ad-
hesion to the burner.
The burner nozzle must be properly
connected to the opposite pole in the
ionisation current return line.
Under normal power supply condi-
tions, the opposite pole - N - is tied to
ground potential. Connection of
ground and/or protective grounding
terminal to burner ground is sufficient.
If a buffer transformer is used, it is
absolutely necessary that the burner
ground is connected to the pole which
is used instead of N. Otherwise the
ionisation current has no return line.
The situation may occur that, despite
a proper flame and proper arrange-
ment of the electrode, no or only a
weak ionisation current can flow.
3 ... 4
The material of the ionisation elec-
trode and the insulation must be heat-
resistant. A proven material is Kanthal
Regulator, gas switch
for electrodes and a ceramic insula-
Exhaust gas temperature
LP gas valve
tion made of aluminium oxide. The
Ignition
insulation resistance should be more
Ignition valve Y1
Flame signal
than 50 MΩ.
Main gas valve Y2
Fault interlock

Measuring the monitor current

The intensity of the ionisation current
Regulator, gas switch
Exhaust gas temperature
can be measured by means of a DC
LP gas valve
Ignition
micro-ammeter. The current intensity
Ignition valve Y1
should not undershoot 6 µA during
Flame signal
Main gas valve Y2
operation. The maximum reachable
Fault interlock
ionisation current is approx. 50 µA.
Fault shut-down takes place when the
Regulator, gas switch
ionisation current undershoots approx.
Exhaust gas temperature
1 µA.
LP gas valve
Ignition
For measurement purposes, the mi-
Ignition valve Y1
Flame signal
cro-ammeter is switched between the
Main gas valve Y2
Fault interlock
ionisation electrode and the connec-
tion plug.
Regulator, gas switch
Test equipment connection
Exhaust gas temperature
LP gas valve
Ignition
Ignition valve Y1
Flame signal
Main gas valve Y2
Ionisation
Fault interlock
100 µF
approx. 3 s
approx. 5 s
+
< 50 s
< 1 s
approx. 5 s
= 0...100 µA
Installation and operating instruc-
tions
Installation
The automatic gas burner control can
be installed in any position.

Electrical connection

Wiring has to be performed in compli-
ance with the local prevailing regula-
tions and the wiring diagram.
Startup
Before startup, check whether all con-
nections are correct.
Check the following safety functions
during startup:
1. Switch off regulators, switches and
limiters.
2. Refer to gas pressure switch switch-
ing points
3. Flame detector
Interrupt ionisation line and/or per-
form a short circuit between elec-
trode and ground.
4. Test: Switch-off via exhaust gas
temperature
DGAI.69F
IE
-
Fault unlocking facility
In case of fault, the DGAI.65F is un-
locked by means of an external con-
tact.
Fuses
An internal fuse (4 A) protects the
equipment from an output-side short
circuit. The fuses cannot be replaced.
For this reason, only DUNGS person-
nel may check and repair the auto-
matic burner control.
External backup of the automatic gas
burner control by means of a 6.3 A
slow-blow and/or 10 A quick-acting
back-up fuse.
Refer to the permitted
switching capacities.
If a fuse is defective, check the
safety function of the monitoring
device, otherwise the contact may
be welded by a short circuit.
If you do not observe these
installation and operating
instructions, it may result in per-
sonal injury or material damage.
For this reason, strictly keep to the
instructions. The warranty for the
equipment will expire on any at-
tempt to access the electronic cir-
cuits, i.e. automatically when the
seal is broken.
The effects of leak search
spray and similar substanc-
es may cause dangerous flame-
simulating conditions on ionisa-
tion electrodes and conductors,
e.g. ionisation ammeters.
Therefore please handle leak
search sprays and similar sub-
stances with extreme care so that
they are only applied to the leak
test points.
If it is not possible to limit the use
of these substances, ionisation
electrodes and conductors must
be protected before applying the
substances. It is not sufficient to
merely wipe off the leak search
spray substance after application.