Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
APPENDIX M – ULTRA-LOW NOx CALIBRATION
OMM-0082_0J
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
Page
185
of
192
GF-130
Ph.: 800-526-0288
05/21/2014
APPENDIX M – ULTRA-LOW NOx CALIBRATION
M-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.
NOTE
The instructions below do not apply to units running Propane 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 4.3. 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
.
