Grant Spira Series - Burner Operational Modes

Burner
40
9 Burner
9.1 Burner Operation
The burner controls the pellet feed
auger, flue fan, boiler temperature and
also the boiler and brazier cleaning
systems. The burner comes with a
display screen and six control buttons.
These buttons are to access the menus
and control the burner functions.
The burner is equipped with a brazier
where the combustion of the wood
pellets takes place within the boiler.
The self cleaning device on the brazier
is automatically activated after the pellet
feed auger run time has exceeded a
predetermined set time. The pellet feed
auger run time for brazier and boiler
cleaning is pre-set in the burner menu.
The temperature of the water within the
boiler is controlled via a thermistor to
the burner. The thermistor is inserted
into the boiler water jacket and is used
by the burner to control the modulation
of the boiler output.
The boiler has a set point temperature.
This is the target flow temperature from
the boiler. As the temperature of the
boiler increases and reaches the set
point less 5°C the output of the boiler is
reduced by one step. Each subsequent
1°C increase in boiler temperature
reduces the output of the boiler by one
modulation step until the temperature
reaches the set point plus 5°C. At this
point the boiler output is ‘MINIMUM
FLAME’ which is minimum output
setting of the boiler. The percentage
increase or decrease in power is
calculated on the rate of temperature
change. The sequence of operation is
described in Section 9.3.
9.2 Burner Operational Modes
‘BOILER WAIT THERMOSTAT’:
(operation code 03) Boiler is in standby
awaiting the following;
• A switched live input signal from a
control system.
• The boiler temperature to drop
below the ‘DELTA RESTART’
temperature. (‘DELTA RESTART’ is
the temperature the burner restarts
after maximum temperature has
been reached).
• The ON/STANDBY switch on
the control panel is set to the ‘ON’
position.
‘WAIT PRELOAD BRAZIER’:
(operation code 40) Initial loading of
pellets into the brazier to enable
combustion to start.
• Activated with a switched live input
signal and/or temperature drops
below the ‘DELTA RESTART’
temperature.
• Deactivated after time exceeds
‘T08’.
‘WAIT LIGHTING’ – IGNITION:
(operation code 41) Period of time given
for pellets to light.
• Activated after ‘PRE LOAD’
operation is complete.
• Deactivated once photocell lux
reading exceeds ‘FLAME ON’
setting.
‘WAIT LIGHTING’–FLAME
STABILISATION: (operation code 45)
Period of time to allow flame stabilise
after pellets have ignited.
• Activated after ignition mode.
• Deactivated after time exceeds
‘T13’.
‘WAIT LIGHTING’ –LIGHTING FEED
REDUCED: (operation code 42) Period
of time intermittent quantities of pellets
supplied to the brazier to increase the
flame.
• Activated after -‘WAIT LIGHTING’
flame stabilization mode.
• Deactivated after time exceeds
‘T09’.
‘PELLET BURNER FIRING’: Power
100% (operation code 13) Flame is fully
developed and boiler is operating on full
power.
• Activated after –‘WAIT LIGHTING’
lighting feed reduced mode
• Deactivated after temperature is
within ‘TEMP DELTA’ range.
‘PELLET BURNER FIRING’: Power
(modulating) (operation code 13) Flame
is reduced and boiler output is
modulating.
• Activated once the boiler
temperature is within the ‘TEMP
DELTA’ range.
• Deactivated after temperature
exceeds the ‘TEMP DELTA’ range.
‘PELLET BURNER FIRING’: Power
(minimum) (operation code 13) Flame is
reduced and boiler is at its minimum
output.
• Activated once the boiler
temperature exceeds the ‘TEMP
DELTA’ range.
• Deactivated after the temperature
exceeds ‘TEMP OFF H2o.
‘TURNING OFF BRAZIER’: (Operation
code 14). Burn down period to remove
any pellets remaining in the brazier.
• Activated once switched live input
signal is switched off or the boiler
temperature exceeds ‘TEMP OFF
H2o’ setting.
• Deactivated once photocell lux
reading has dropped below the
‘FLAME ON’ setting less.
‘WAIT POST PURGE’: (operation code
26) Period of time after burn down is
complete to ensure no unburnt pellets
ignite.
• Activated after ‘TUNNING OFF
BRAZIER’ is complete.
• Deactivated after time exceeds
‘T22’.