AERCO BMK 6000 - Manual (Page 64)

Benchmark 6000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 4 – INITIAL START-UP
Page 64 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.)
11.
Using the ▲ arrow key, increase the valve open position to 100%. Verify that the gas
pressure on the downstream side of the SSOV settles within the required range of 7.9 ±
0.4” W.C. Readjust the gas pressure if necessary.
12. With the valve position at 100%, insert the combustion analyzer probe into the flue probe
opening and allow enough time for the combustion analyzer reading to stabilize.
13. Compare the oxygen readings on the combustion analyzer to the on-board O
2
sensor value
displayed in the Operating Menu of the C-More Control Panel. If the values differ by more
than ±1.5% and your combustion analyzer is correctly calibrated, the on-board O2 sensor
may be defective and need to be replaced.
14. Compare the measured oxygen level to the oxygen range shown below. Also, ensure that
the nitrogen oxide (NOx) and carbon monoxide (CO) readings do not exceed the values
shown. If you are not in a “NOx-limited” area and/or do not have a NOx measurement in
your analyzer, set the oxygen (O
2
) at 5.1% ± 0.5%.
Combustion Calibration Readings
Valve Position Oxygen (O
2
) % Nitrogen Oxide (NOx) Carbon Monoxide (CO)
100% 5.4% - 6.3% <20 ppm <100 ppm
15. If the oxygen level is not within the required tolerance, the gas pressure on the
downstream side of the SSOV must be adjusted using the gas pressure adjustment screw
on the SSOV (Figure 4-3). Slowly rotate the gas pressure adjustment (approximately 1/4-
turn increments). Allow the combustion analyzer to stabilize following each adjustment.
Clockwise rotation reduces the oxygen level, while counterclockwise rotation increases the
oxygen level.
16. Once the oxygen level is within the specified range at 100%, record the O
2
, NOx and CO
readings on the Combustion Calibration Data Sheets provided with the unit.
17. Lower the valve position to 80%
using the ▼arrow key.
NOTE
The remaining combustion calibration steps are performed using
the Combustion Cal Menu included in the C-More Control System.
The combustion calibration control functions will be used to adjust
the oxygen level (%) at valve positions of 80%, 60%, 45%, 30%
and 18% as described in the following steps. These steps assume
that the inlet air temperature is within the range of 50°F to 100°F. If
NOx readings exceed the target values shown, increase the O
2
level up to 1% higher than the listed calibration range. Record the
increased O
2
value on the Combustion Calibration sheet.