ENGLISH
17 / 36
0006080872_201711
DESCRIPTION OF OPERATION WITH LIQUID
FUEL
FURTHER INSTRUCTIONS TO START A MIXED BURNER
We recommend performing the first ignition with liquid fuel (fuel
change-over switch) because, in this case, the output is conditioned
by the nozzle that is used whereas the output of the natural gas can
be varied as required by adjusting the flow rate regulator.
Closing the ON - OFF switch, if the thermostats are closed, the
voltage reaches the command and control equipment which starts
its operation cycle. This switches on the fan motor and the ignition
transformer.
The motor turns the fan that carries out an air wash of the combustion
chamber and, at the same time, the fuel pump that causes circulation
in the ducts, expelling any gas bubbles through the return valve. This
pre-washing phase ends with the opening of the operating solenoid
valves that makes it possible for the fuel to reach the nozzle and enter
the combustion chamber finely atomised.
As soon as the atomized fuel exits the nozzle, it is set on fire by the
spark present between the electrodes since the start of the motor.
Once the flame appears in the combustion chamber, the burner is
controlled and commanded by the flame control equipment and by
the thermostats.
The control equipment follows the program and switches the ignition
transformer off. When the temperature or the pressure in the boiler
reaches that set by the thermostat or pressure switch, the latter stops
the burner.
Subsequently, if the temperature of pressure decreases below the
lower thermostat or pressure switch threshold value, the burner will
switch on again.
If, for any reason, the flame is lost during burner operation, the flame
control device immediately cuts off the power and automatically
switches off the solenoid valve which intercepts the nozzle flow.
The ignition phase is repeated in this manner and, if the flame
reignites normally, the burner will return to normal operation.
Otherwise (irregular flame or no flame), the equipment will shut-down
automatically.
The ignition phase is repeated in this manner and, if the flame
reignites normally, the burner will return to normal operation.
Otherwise (irregular flame or no flame), the equipment will shut-down
automatically.
Summary of Contents for COMIST 20
Page 2: ......
Page 36: ...ITALIANO 34 36 0006080872_201711 SCHEMI ELETTRICI ...
Page 38: ......
Page 72: ...ENGLISH 34 36 0006080872_201711 WIRING DIAGRAMS ...
Page 74: ......
Page 75: ......