Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 4 – INITIAL START-UP
Page
64
of
192
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0082_0J
05/21/2014
Ph.: 800-526-0288
GF-130
PROPANE Combustion Calibration –
Continued
27.
Once the oxygen level is within the specified range at 80%, press the
ENTER
key to
store the selected blower output voltage for the 80% valve position. Record all readings
on the Combustion Calibration Sheets provided.
28.
Repeat steps 20 through 27 for valve positions of 60%, 45%, 30% and 18%* (see *NOTE
below). The oxygen (O
2
), nitrogen oxide (NOx) and carbon monoxide (CO) should remain
within the same limits for all valve positions as shown in the following table.
*NOTE
Set the Valve Position at 18% but make adjustments to the Combustion
Calibration value designated as 16%.
NOTE
If NOx readings exceed the target values shown (<30 ppm), increase the
O
2
level up to 1% higher than the listed calibration range shown in the
table. Record the increased O
2
value on the Combustion Calibration sheet.
Propane Combustion Calibration Readings
Valve Position
Oxygen (O
2
) %
Nitrogen Oxide
(NOx)
Carbon Monoxide
(CO)
60%
5% - 6%
<30 ppm
<100 ppm
45%
5% - 6%
<30 ppm
<100 ppm
30%
5.8% - 6.8%
<30 ppm
<100 ppm
18%
5% - 6%
<30 ppm
<100 ppm
29.
If the oxygen level at the 18% valve position is too high and the Blower voltage is at the
minimum value, you can adjust the idle screw (TAC valve) which is recessed in the top of
the Air/Fuel Valve (see Appendix G). Rotate the screw 1/2 turn clockwise (CW) to add fuel
and reduce the O
2
to the specified level. Recalibration MUST be performed again from
60% down to 18% after making a change to the idle screw (TAC valve).
30.
This completes the PROPANE combustion calibration procedures.
4.5 REASSEMBLY AFTER COMBUSTION CALIBRATION
Once the combustion calibration adjustments are properly set, the unit can be reassembled for
service operation.
Reassembly After Combustion Calibration
1.
Set the
ON/OFF
switch in the
OFF
position.
2.
Disconnect AC power from the unit.
3.
Shut off the gas supply to the unit.
4.
Remove the manometer and barbed fittings and reinstall the NPT plug using a suitable
pipe thread compound.
