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

INITIAL START-UP
21. If the oxygen level is not within the specified
range, adjust the level using the up (Λ) and
down (V) arrow keys on the VFD. Pressing
the up (Λ) arrow key will increase oxygen
level and pressing the down (V) arrow key
will decrease the oxygen level.
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 using
the using the up (Λ) and down (V) arrow
keys on the VFD 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. Using up (Λ) and down (V) arrow keys on
the VFD, 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. Using the VFD up (Λ) and down (V) arrow
keys, 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:
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 using
the VFD up (Λ) and down (V) arrow keys to
obtain the required reading at the 14% firing
rate.
IMPORTANT
Repeat steps 18 through 29 until the VFD
does not require adjustment when
sequencing from 70% to 14%.
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.
4-5