p.
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If the above described conditions are satisfied, then the control board performs algorithm as
follows:
The fuel transport auger is activated, the electric heater is activated and air fan are
running simultaneously;
After a factory set (predefined) period of time has ran out, (during this period the so
called “initial fuel” mass has been charged to the combustion chamber), the electric
motor of the fuel transport auger will be stopped (the ignition heater is active
however);
After certain period of time the photosensor of the burner should recognize stable
combustion process by the emitted visible light and the electrical ignition element
will be powered off. This is followed by graduate increment of the thermal capacity
(i.e. the fuel flow rate) of the burner and after certain period of time the nominal
thermal capacity will be reached. In case that the photosensor does not sense
intensive light, i.e. there is no combustion process, or it is rather lean, than the
control board of the burner will initiate new attempt to start the burner, the above
described algorithm will be repeated. The total number of ignition attempts is
however limited. In case that this limit has been passed, then burner will go into
alarm mode and will not function until manual assistance is performed (for example
bunker’s charge with fuel, solving a problem, etc.) and the burner is restarted;
In case that the fuel has been ignited, the burner goes into nominal operation mode,
which is performed by periodic fuel transport to the combustion chamber of the
burner, followed by a certain interval, utilized for fuel combustion. The periods for
fuel charge and combustion are predefined in the operating firmware of the control
module, the thermal capacity of the burner is however changed by setting the
operating stage of the burner;
ATTENTION:
The choice of the maximal thermal capacity stage – 5
th
is not
recommended, this stage is available in order to utilize relatively low calorific value
fuel or temporary demand of increased heat consumption rate. It is recommended to
operate the pellet burner in the operating range of 1
st
to 4
th
thermal capacity stages, at
4
th
stage the burner achieves its nominal thermal capacity;
When in the burner’s control module is used NTC sensor for measurement of the
operating temperature of the circulating water :
-
At approaching the temperature of the circulating water set-point the control
module decreases the burner’s operating thermal capacity (i.e. the control
module operates the burner in modulating mode)
;
-
At decreasing the temperature of the circulating water, the burner’s control
module restores the set thermal capacity
;
In case that the START signal goes off (for any reason – room thermostat for
example, etc.) the burner will go into stand-by mode, following the algorithm,
described above;
In case that in stand-by mode the burner receives START signal, the control board
will perform the above described algorithm in order to initiate ignition and continue
into nominal thermal capacity mode; The same operating algorithm will be
performed when the temperature of the circulating water is below the temperature
set-point (in case the burner is equipped with NTC sensor);
In case the first fuel dose is not ignited due to any reason, the control board of the
unit will automatically start new ignition procedure. The total number of ignition
attempts is limited to 2 (factory preset value). In case of two failures at ignition,
there could be fuel particles on the burner’s grate, which should be cleaned.
ATTENTION : if the accumulated fuel is not cleaned after ignition failures, any
new attempt to ignite the fuel particles will be accompanied with intensive smoke
release and eventually blast ignition, which could eventually result even in
mechanical damages of the burner and the heat consumer unit;
