Benchmark 6000 Boiler Installation, Operation & Maintenance Manual
APPENDIX N – ULTRA-LOW NOX CALIBRATION
OMM-0086_0D
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
Page
205
of
210
GF-133
Ph.: 800-526-0288
03/20/14
APPENDIX N – ULTRA-LOW NOx CALIBRATION
N-1. ULTRA-LOW NOx COMBUSTION CALIBRATION
The procedures provided in this Appendix are used to combustion calibrate the boiler to
produce ultra-low NOx emissions of
less than 9 ppm
when running on natural gas.
If the ultra-low NOx requirement was specified on the Sales Order, the Benchmark Boiler was
combustion calibrated at the factory prior to shipping. However, recalibration as part of initial
start-up is necessary due to changes in the local altitude, gas BTU content, gas supply piping
and supply regulators. Factory Test Data sheets are shipped with each unit. These sheets must
be filled out and returned to AERCO for proper Warranty Validation.
Prior to performing the procedure in this Appendix, the boiler must be set up as described in
Chapter 4, section 4.1 through the
low NOx
combustion calibration in section 4.4. Once that is
complete, perform the following steps to combustion calibrate the boiler to the
ultra-low NOx
requirement of less than 9 ppm.
IT IS IMPORTANT TO PERFORM THE FOLLOWING PROCEDURE AS OUTLINED BELOW. THIS
WILL KEEP READJUSTMENTS TO A MINIMUM AND PROVIDE OPTIMUM PERFORMANCE
.
Ultra-Low NOx Natural Gas Combustion Calibration
1. Open the water supply and return valves to the unit and ensure that the system pumps
are running.
2. Open the natural gas supply valve(s) to the unit.
3. Set the control panel
ON/OFF
switch to the
OFF
position
4.
Turn on external ac power to the unit. The display will show loss of power and the time and date.
5.
Set the unit to the manual mode by pressing the
AUTO/MAN
KEY.
A flashing
manual valve
position
message will be displayed with the present position in
%
. Also, the
Manual
led will
light.
6. Adjust the air/fuel valve position to
0%
by pressing the
▼ arrow key.
7. Ensure that the leak detection ball valve downstream of the SSOV is open.
8.
Set the
ON/OFF
switch to the
ON
position
.
9. Change the valve position to
30%
using the ▲ arrow key. The unit should begin its start
sequence and fire.
10. Next, verify that the gas pressure downstream of the SSOV is set to the range of
2.0 ±
0.4” W.C.
If gas pressure adjustment is required, remove the brass hex nut on the
SSOV actuator to access the gas pressure adjustment screw (Figure L-1). Make gas
pressure adjustments using a flat-tip screwdriver to obtain a gas pressure within the
range of
2.0 ± 0.4” W.C.