AERCO BMK 3.0 LN Nat. Gas APRIL 2009 - Manual (Page 122)

APPENDIX K
K-4
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. Using the
up (Λ) arrow key will increase oxygen level
and 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 20. 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. Next, set the firing rate to 30% and select
VFD parameter 19. 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
25. Adjust the oxygen level as necessary to
obtain the required reading at the 30% firing
rate.
26. Finally, reduce the firing rate to 14% and
select VFD parameter 15. 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
27. Adjust the oxygen level as necessary to
obtain the required reading at the 14% firing
rate.
28. This completes the combustion calibration
procedure.
29. Return to Chapter 4, paragraphs 4.4 and 4.5
for Unit Reassembly instructions and
information on Over-Temperature Limit
Switches.