AERCO BMK 3.0 LN Nat. Gas Jan 2009 - Manual (Page 37)

INITIAL START-UP
4-5
22. Once the oxygen level is within the specified
range at 70%, lower the firing rate to 50%
and select VFD parameter 64. The oxygen
level at the 50% firing rate should be as
shown below.
Combustion Oxygen Level at
50% Firing Rate
Oxygen %
± 0.2
Carbon
Monoxide NOx
7.0 % <50 ppm <20 ppm
23. Adjust the oxygen level as necessary to
obtain the required reading at the 50% firing
rate.
24. Once the oxygen level is within the specified
range at 50%, lower the firing rate to 40%
and select VFD parameter 63. The oxygen
level at the 40% firing rate should be as
shown below.
Combustion Oxygen Level at
40% Firing Rate
Oxygen %
± 0.2
Carbon
Monoxide NOx
7.8% <50 ppm <20 ppm
25. Adjust the oxygen level as necessary to
obtain the required reading at the 40% firing
rate.
26. Next, set the firing rate to 30% and select
VFD parameter 62. The oxygen level at the
30% firing rate should be as shown below.
Combustion Oxygen Level at
30% Firing Rate
Oxygen %
± 0.2
Carbon
Monoxide NOx
8.0 % <50 ppm <20 ppm
27. Adjust the oxygen level as necessary to
obtain the required reading at the 30% firing
rate.
28. Finally, reduce the firing rate to 14% and
select VFD parameter 61. The oxygen level
at the 14% firing rate should be as shown in
the following tabular listing:
NOTE
At a 14% fire rate, if parameter 61 is
above 326, the VFD software will use 326
by default. 326 corresponds to a
frequency of 32.6 Hz.
Combustion Oxygen Level at
14% Firing Rate
Oxygen %
± 0.2
Carbon
Monoxide NOx
8.5 % <50 ppm <20 ppm
29. Adjust the oxygen level as necessary to
obtain the required reading at the 14% firing
rate.
30. This completes the combustion calibration
procedures.
4.4 UNIT REASSEMBLY
Once the combustion calibration adjustments
are properly set, the unit can be reassembled for
service operation.
1. Set the ON/OFF switch in the OFF position.
2. Disconnect AC power from the unit.
3. Shut off the gas supply to the unit.
4. Remove the manometer and barbed fittings
and reinstall the NPT plug using a suitable
pipe thread compound.
5. Remove the combustion analyzer probe
from the vent hole. Replace the NPT plug in
the vent hole using a suitable pipe joint
compound.
6. Replace the unit’s side panels and front
door.