elco VECTRON F 02.118 DUO Betriebsanleitung Seite 25

Operation
Functional description for LGB 22
Programme flow
– The variable thermostat calls for heat
– The control device's control
programme starts
– The burner motor only starts if the air
pressure control device contact is off
and the gas pressure control device
shows sufficient gas pressure.
– Pre-ventilation time approx. 40 s.
LGB functional diagram
Control unit LGB 22
Ignition
Valve
transformer 1 st stage
Ioni-
sation
tw = waiting time start 9 sec
tvl = pre-ignition time / pre-ventilation time
ts = safety time 2 - 5 sec
tv2 = post-ignition time 10 sec
During the pre-ventilation time the
following takes place
– the fan pressure is monitored
– the furnace is monitored for flame
signals.
After the pre-ventilation time
– the ignition is switched on
– the main solenoid valve and safety
solenoid valve are opened
– the burner starts up with min. furnace
heat output
Fuse
Limiter
Boiler Regulator
Gas pressure switch
Valve Fault
2 d stage
info
Air pressure
switch
Burner
motor
Thermostat ON
Start with flame formation
Operation
Thermostat ON
Start without flame formation
Fault
06/2005 - Art. Nr. 13 018 217A
Monitoring
The flame is monitored using an
ionisation probe. The probe is mounted
separately on the gas head.
During operation of the burner an
ionised zone is created in the gas
flame, through which a rectified current
flows from the probe to the burner
nozzle. The ionisation current must be
at least 8 µA.
In the event of a shortcircuit between
the probe and the burner body, the
burner switches to fault.
Safety measures
Should no flame be created at the
burner's first stage (gas release), then
the gas supply is interrupted after a
max. 3 second safety period.
In the event of flame failure during
operation the gas supply is immediately
cut off and the boiler cutout device
activates the fault cut-out within a
second.
Lack of air during both pre-ventilation
and operation will trigger fault cut-out.
In the event of lack of gas, the burner
does not operate. In the event of lack of
gas during operation the gas valve
closes and the burner shuts off. This
does not bring about fault cut-out. After
the build-up of gas pressure, the burner
Release
restarts automatically.
button
In the event of an interruption in
electricity supply, the gas supply is
immediately blocked. The burner
switches off. When the power is back,
the burner starts up automatically.
EN
25