AERCO BMK 6000 - Manual (Page 66)

Benchmark 6000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 4 – INITIAL START-UP
Page 66 of 210 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0086_0D
03/20/14
Ph.: 800-526-0288
GF-133
Natural Gas Combustion Calibration (Cont.)
28. Repeat steps 20 through 27 for valve positions of 50%, 40%, 30% and 18%* (see *NOTE
below). The oxygen (O
2
), nitrogen oxide (NOx) and carbon monoxide (CO) should remain
within the same limits for all valve positions as shown in the following table.
*NOTE
Set the Valve Position at 18% but make adjustments to the
Combustion Calibration value designated as 16%.
NOTE
If NOx readings exceed the target values shown (<20 ppm),
increase the O
2
level up to 1% higher than the listed calibration
range shown in the table. Record the increased O
2
value on the
Combustion Calibration sheet.
Combustion Calibration Readings
Valve Position Oxygen (O
2
) % Nitrogen Oxide (NOx) Carbon Monoxide (CO)
50% 6% - 7% <20 ppm <100 ppm
40% 6% - 7% <20 ppm <100 ppm
30% 6% - 7% <20 ppm <100 ppm
18% 5% - 7% <20 ppm <100 ppm
29. If the oxygen level at the 18% valve position is too high and the Blower voltage is at the
minimum value, you can adjust the idle screw (TAC valve) which is recessed in the top of
the Air/Fuel Valve (see Figure 4-4, below). Rotate the screw 1/2 turn clockwise (CW) to
add fuel and reduce the O
2
to the specified level. Recalibration MUST be performed again
from 50% down to 14% after making a change to the idle screw (TAC valve).
30. This completes the Natural Gas combustion calibration procedures.