Joannes G35 gas Manual De Uso Y Mantenimiento página 63

pag. 60
CONTROL OF IONIZATION CURRENT
The minimum value of 2 A shall be respected and it shall not show strong oscillations.
1
µA
CONNECTION OF THE MICROAMMETER
FUEL CONTROL
In order to achieve the best fuel efficiency with respect to the environment, it is recommended to effect the control
and adjustment of the fuel by the proper instruments.
The fundamental values to be considered are the following:
CO . It shows the excess of air by which the combustion occurs. When the air is increased the value of CO %
2 2
decreases. When the combustion air decreases, the CO increases. Acceptable values are 8,5 – 10% NATURAL GAS,
2
11-12% B/P.
CO. It shows the presence of unburned gas. The CO lowers the fuel efficiency and represents a danger as it is
poisonous. It is a sign of an imperfect combustion and it usually occurs when the air is lacking. Max. admitted value,
CO = 0,1% volume.
Temperature of fumes. It shows the dispersion of heat through the flue. The higher the temperature, the greater the
dispersions and the lower the combustion efficiency. When the temperature is too high it is necessary to decrease
the quantity of burnt gas. Good values of temperature are those included between 160°C and 220°C.
N.B. : In a few countries the regulations in force may require different settings from those
reported and also demand the respect of different parameters.
STARTING
Check the position of the ignition electrode tips and the position of the control electrode. Check the proper working
of the gas and air pressure switches. After closing the thermostatic and gas pressure switch line, the unit gives its
consent for the starting of the motor. During this period the unit self-checks its integrity. If the self-check is positive,
the cycle continues and at the end of the pre-ventilation period (TPR washing of the combustion chamber) the consent
to the transformer for the release of the electrodes and the opening of the solenoid valve is given. Within safety time
TS the stabilisation of the flame has to occur otherwise the unit locks.
SWITCHING OFF OF THE UNIT
In case the unit is not going to operate for long, close the gas cock and disconnect from mains.