Finterm Joannes G 50/2 Manual De Instrucciones De Manejo Y Mantenimiento página 54

STARTING THE BURNER AND ADJUSTING THE GAS FLAME
– Open the air valve by approx. 1/3;
– set at about 1/3 the delivery of the main solenoid valve first stage;
– open the gas valve;
– turn the ON/OFF switch to ON position and the MIN-MAX switch on MIN position; then turn the
master switch to ON to start the burner.
After the pre-ventilation time the burner will start and will operate with the first gas stage only.
Set the air flow depending on the gas flow rate to be achieved for the first stage.
Turn the MIN-MAX switch to MAX. position. If the pressure switch or the self-regulating thermostat
require heat, the servo control will soon cause the burner to operate on both stages. Adjust the
second stage delivery.
The air shutter opening shall be adjusted also for the maximum delivery.
– The gas pressure switch shall be set at a pressure level which, in case of gas pressure reduction
in the line, will stop the burner before mixtures are made that might impair the burner proper ope-
ration.
FUEL CONTROL
In order to obtain the best combustion efficiency and, with respect to the environment, the control
and setting of the fuel shall be effected by the proper instruments.
The fundamental values to be considered are:
– CO . It shows by which excess of air the combustion occurs; when the air is increased, the value
2
of CO decreases. When the combustion air is decreased the value of CO
2
values are 8,5-10% NATURAL GAS and 11-12% B/P.
– CO. It shows the presence of unburned gas; the CO decreases the combustion efficiency and
represents a danger as it is poisonous. It shows an imperfect combustion and it usually occurs
when the air is inadequate.
– Temperature of fumes. This is a value representing the heat dispersion through the stack; the
higher the temperature, the higher the dispersions and the lower the combustion efficiency. When
the temperature is too high it is better to decrease the quantity of burned gas. Good values of
temperature are those included between 160°C and 220°C.
IONISATION CURRENT
After the settings and the combustion tests, it is necessary to check that the control electrode is
properly positioned; this is achieved by the measuring of the ionisation current.
Use a microammeter with bottom 10 ua to be inserted to the electrode. The minimum current value
shall be 5 ua and be stable enough.
The flame control circuit is usually insensible to the negative influences of the ignition spark on the
ionising current. If the disturbing influences of the ignition spark on the ionisation current are exces-
sive it is necessary to invert the polarity of the electric connections of the ignition transformer pri-
mary and/or invert the location of the ignition electrode as to the ionisation one.
N.B. In a few countries the current regulations may require different settings from those
reported and require the respect of different parameters.
LONG BLOWOUT
When the burner is to remain idle for some time, close the gas valve and disconnect from mains.
TRANSFORMATION FROM NATURAL
GAS INTO B/P.
A specific burner is not contemplated. If
you want to fit the burner to another kind of
combustible gas, please consider that,
owing to the different conditions originating
with the use of B/P, it is necessary to carry
out the replacement of the deflector.
Assembly of the deflector
Loosen screws A, remove deflector B and
replace it with a ring C, that differentiates
from type B for the smaller quantity of gas
outlets.
OPERATING WITH DIFFERENT TYPES OF GAS
17
increases. Acceptable
2
code 274231 G 50/2
code 274232 G 70/2
B
A
FIG. 18
C