AERCO BMK 3.0 LN Nat. Gas Jan 2009 - Manual (Page 35)

INITIAL START-UP
4-3
5. Set the unit to the Manual Mode by pressing
the AUTO/MAN key. A flashing Manual Fire
Rate
message will be displayed with the
present rate in %. Also, the MANUAL LED
will light.
6. Adjust the fire rate to 0% by pressing the ▼
arrow key.
7. Ensure that the leak detection ball valve
down-stream of SSOV No. 2 is open.
8. Set the ON/OFF switch to the ON position.
9. Change the fire rate to 29% using the ▲
arrow key. The unit should begin its start
sequence and fire.
10. Next, verify that the gas pressure
downstream of SSOV No. 1 is 1.8” W.C. for
both FM and IRI gas trains. If gas pressure
adjustment is required, remove the brass
hex nut on downstream SSOV No. 1
containing the gas pressure regulator
(Figure 4-3). Make gas regulator adjust-
ments using a flat-tip screwdriver to obtain
1.8” W.C.
Figure 4-3
Regulator Adjustment Screw Location
11. Raise the firing rate to 100% and verify that
the gas pressure downstream of SSOV No.
1 remains at 1.8” W.C. Readjust pressure if
necessary.
12. With the firing rate at 100%, insert the
combustion analyzer probe into the flue
probe opening and allow enough time for the
combustion analyzer to settle.
13. Compare the measured oxygen level to the
oxygen range for the inlet air temperature
shown in Table 4-1. Also, ensure that the
carbon monoxide (CO) and nitrogen oxide
(NOx) readings do not exceed the values
shown.
Table 4-1
Combustion Oxygen Levels for a 100%
Firing Rate
Inlet Air
Temp
Oxygen %
± 0.2
Carbon
Monoxide NOx
>100°F 4.8 % <100 ppm <30 ppm
90°F 5.0 % <100 ppm <30 ppm
80°F 5.2 % <100 ppm <30 ppm
<70°F 5.3 % <100 ppm <30 ppm
14. If necessary, adjust the iris air damper
shown in Figure 4-4 until the oxygen level is
within the range specified in Table 4-1.
15. Once the oxygen level is within the specified
range at 100%, lower the firing rate to 70%.