Benchmark 6000 Boiler Installation, Operation & Maintenance Manual
APPENDIX N – ULTRA-LOW NOX CALIBRATION
Page
206
of
210
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0086_0D
03/20/14
Ph.: 800-526-0288
GF-133
Ultra-Low NOx Natural Gas Combustion Calibration (Cont.)
Figure N-1: Gas Pressure Adjustment Screw Location
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 range of
2.0 ± 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 ±0.5%, have your combustion analyzer calibration checked as soon as
possible. If the readings differ by more than ±1.5%, use the on-board O
2
sensor to
calibrate the unit. Have your combustion analyzer serviced.
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.
Ultra-Low NOx
Combustion Calibration Readings
Valve Position
Oxygen (O
2
) %
Nitrogen Oxide (NOx)
Carbon Monoxide (CO)
100%
5% - 7%
<9 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 N-1). 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.
TYPICAL SSOV ACTUATOR WITH REGULATOR
BRASS HEAD CAP
(Remove to access
Gas Pressure
Adjustment Screw)
