After commissioning the burner, check air pressure switch settings. See
section
Adjusting combustion differential air pressure switch
.
4.16 Activating FGR
Burners equipped with FGR can also be used without FGR. Whenever
you activate and deactivate FGR, you will need to recheck fuel–air ratio
curves.
FGR can be activated from:
Params. & Display
→
Flue gas recirc.
→
FGR mode
→
TC autodeact
→
It is recommended to commission the plant first without flue gas recirculation (FGR).
Thus the fuel-air ratio control system is set as if the plant operated without the FGR
function.
When all other settings have been made, create FGR curve points at ratio curve. The
FGR function will become active after you have stored the curve point settings.
During the time the curve menu is in use, the state of the FGR function does not
change. This means that the AUX3 for FGR is still at the
FGR closed
position until
parameter setting is completed.
The parameters for FGR mode have been set at the factory. The commissioning
personnel will adjust the settings at start-up if needed.
For further instructions, see the section
Setting FGR curve points
.
4.17 Setting FGR curve points
The FGR curve points are set at the fuel-air ratio curve. During the time the curve menu
is in use, the state of the FGR function does not change. This means that if the AUX3 is
still at the
ignition position
when setting parameters, it maintains the position until the
curve setting is completed.
At this position, the recirculation duct remains in
ignition position
, and the AUX3 is
marked with
#
on the screen. The position value of the AUX3 can be changed, but it
will not follow the readjustment for that period of time. The changed value can also be
stored.
If the AUX3 is not marked with
#
when setting parameters, it is already on the ratio
control curve, and follows the readjustment of the position value immediately.
After time period or temperature is reached, AUX3 will be released and FGR curve can
be made.
Temperature value can be changed from:
Params. & Display
→
Flue gas recirc.
→
ThresholdFGR Gas
→
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