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ENGLISH
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It may happen that the ionisation current is interfered with
by the discharge current of the ignition transformer (the two
currents have a common path on the burner’s “mass”) so
the burner gets locked out due to insufficient ionisation. This
can be remedied by inverting the supply (230V side) of the
ignition transformer. This problem may also be caused by an
insufficient “ground connection” to the burner’s casing.
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In the event that ignition is difficult it is advisable to use the
ignition flow proceeding with the inverter “VS” parameter
adjustments (see chapter FREQUENCY CONVERTER)
• M i n i m u m t h e r m a l o u t p u t a d j u s t m e n t
Put the burner to the minimum modulation thermal output position
(air gate control servomotor at minimum) putting the modulation
connector (see section "instructions for manual operation
of burner") to the MIN position. With the aid of appropriate
instruments, carry out the air and gas flow adjustment according
to the procedures subsequently described:
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Vary the rotation speed of the fan motor to the minimum then
proceed with the adjustment of the inverter V1 parameter (see
chapter “FREQUENCY CONVERTER”). Progressively adjust
the motor rotation speed and therefore the air flow by pressing
the in or – keys, checking with appropriate instruments
that the combustion is correct (C02 max= 10%, O2 min=3%,
CO max=0,1%). Check and adjust, if necessary, the air/gas
ratio using the pneumatic valve piston (for this purpose follow
the instructions relative to the installed gas train).
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Having finished the air and gas flow adjustment, check the
actual gas flow to the minimum modulation power rate by
reading the meter. It is essential to check, with a suitable
instrument, that the percentage of carbon monoxide (CO)
present in the fumes does not exceed the limit set by
regulations at the time of installation.
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Store the parameter "alfa1", air gate opening angle to the
minimum power rate, see section "STORING THE WORKING
INTERVAL OF THE AIR SERVOMOTOR".
•
Put the modulation connector switch to the MAX position. The
air adjustment servomotor is put at maximum opening position
and consequently also the gas supply reaches the maximum
thermal output. Afterwards a check is carried out on the quantity
of gas supplied, by reading the meter. Avoid keeping the burner
running if the capacity is greater than the maximum permitted
amount for the boiler, or there is a risk it could be damaged.
To vary the maximum supply of gas output, use the airflow
regulator because the gas output automatically adjusts to the
air supply. It is therefore necessary to use the cam which adjusts
the maximum opening position of the air gate (see adjustment
instructions 0002933651) The opening angle of the air gate
has to be reduced to reduce the gas supply and vice versa. To
vary the air/gas ratio see the instructions for the pneumatic gas
valve installed.
• M a x i m u m t h e r m a l o u t p u t a d j u s t m e n t
With the aid of appropriate instruments, carry out the air and
gas flow adjustment. Vary the rotation speed of the fan motor
then proceed with the adjustment of the inverter V2 parameter
(see chapter “FREQUENCY CONVERTER”). Progressively
adjust the motor rotation speed and therefore the thermal flow
by pressing the in or – keys, checking with appropriate
instruments that the combustion is correct (C0
2
max= 10%, O
2
min=3%, CO max=0,1%). Check and adjust if necessary the
air/gas ratio using the pneumatic valve piston (for this purpose
follow the instructions relative to the installed gas train).
-
Having finished the air and gas flow adjustment, check the
actual gas flow to the maximum modulation power rate by
reading the meter.
-
It is essential to check, with a suitable instrument, that the
percentage of carbon monoxide (CO) present in the fumes
does not exceed the limit set by regulations at the time of
installation.
-
Store the parameter "alfa2", air gate opening angle to the
minimum power rate, see section "STORING THE WORKING
INTERVAL OF THE AIR SERVOMOTOR".
•
After setting operation to the maximum thermal output, it is
necessary to put the air adjustment servomotor to the minimum
flow position, putting the modulation connector to the MIN
position. If necessary, perform the final correction of the air/gas
ratio following the instructions of the installed gas valve. We
recommend that you check combustion using the appropriate
instruments at some points within the modulation range.
From the number of red LEDS on the inverter display during
operation you will notice that in the intermediate points the
motor rotation speed will vary in a continuous way between the
minimum value V1 and the maximum V2. During operation in
modulation the green LED related to V2 will stay lit.
•
Having finished the burner adjustment, store the inverter
settings (see chapter “FREQUENCY CONVERTER”), remove
the modulation connector and restore the connection with the
4-pole connector of the boiler thermostat line.
• Adjusting the air pressure switch
Put the burner to the minimum operating thermal output and
increase the calibration value of the air pressure switch until
the burner goes into lock-out. Adjust the setting of the pressure
switch to a level slightly below the actual air pressure detected
at the minimum setting. Release the burner and check that it
starts up correctly.
•
The pressure switches for checking gas pressure (minimum
and maximum), if installed, prevent the burner from operating
when the gas pressure is not between the expected values. The
specific function of the pressure switches clearly reveals that
the pressure switch for controlling minimum pressure must use
the contact which is closed when the pressure switch detects a
pressure value above the value it is set to, while the pressure
switch for controlling maximum pressure must use the contact
that is closed when the pressure switch detects lower pressure
than the value it is set to. Minimum and maximum gas pressure
switches must be set when the burner is tested. Setting depends
on pressure detected from time to time. Tripping of any of
the
gas pressure switches (in the sense of opening the circuit) will
therefore prevent the equipment and therefore the burner from
working. While the burner is operating (flame lit) the tripping of
the gas pressure switches (circuit opening) causes the burner
to stop immediately. When testing the burner, it is very important
to check that the pressure switches are working properly. By
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