7.4.2
Setting the air/gas ratio (maximum heat input)
1. Unscrew the left-hand plug, which corresponds to the flue gas
measurement point connection.
2. Connect the flue gas analyser to the connection on the left.
Important
Ensure that the opening around the sensor is completely sealed
when taking measurements.
Insert the sensor into the flue gas measurement point to at least
8 cm for SIRIUS THREE FS 50 and SIRIUS THREE FS 70 .
Insert the sensor into the flue gas measurement point to at least
9 cm for SIRIUS THREE FS 90 and SIRIUS THREE FS 110 .
3. Set the boiler's heat input to 100%.
4. Measure the percentage of CO
2
in the flue gases.
5. Compare the values measured with the set point values in the Control
and setting values table.
6. If necessary, adjust the air/gas ratio using the gas flow rate
adjustment screw.
Important
Turn the gas adjustment screw clockwise to reduce the CO
2
content.
Turn the gas adjustment screw counter-clockwise to increase
the CO
2
content.
Caution
Be sure to correctly replace the plug after taking a measurement.
Important
The right-hand connection may be used to analyse the combustion air
to make sure that no flue gas is recirculated in the flue system.
For more information, see
Check-list before commissioning, page 56
CO2 checking and setting values, page 61
Using the boiler according to thermal output, page 88
Fig.65
Connecting the flue gas analyser
MW-3000044-03
1
2
7 Commissioning
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