Instruction Manual

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.