Reassembly - Watts Aerco Benchmark BMK750 Operation And Service Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 4 – INITIAL START-UP
PROPANE Combustion Calibration Instructions
BMK6000
70% 85%
50% 65%
40% 45%
30% 30%
18% 18%
NOTE:
If NOx readings exceed the target values in Table 4-6a and 4-6b, increase the O
1% higher than the listed calibration range shown in the table. Record the increased O
on the Combustion Calibration sheet.
26. If the oxygen level at the lowest valve position is too high, and the Blower voltage is at the
minimum value, you can adjust the TAC screw, which is recessed in the top of the Air/Fuel
Valve (see Figure 4-3). Rotate the screw 1/2 turn clockwise (CW) to add fuel and reduce
the O to the specified level. Recalibration MUST be performed again from 60% or 50%
2
down to the lowest valve position after making a change to the TAC screw.
This completes the PROPANE gas combustion calibration procedure.

4.6 REASSEMBLY

Once the combustion calibration adjustments are properly set, the unit can be reassembled for
service operation.
Reassembly Instructions
1. Set the Enable/Disable switch to the Disable 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.
5. Remove the combustion analyzer probe from the 1/4" vent hole in the exhaust manifold
and then replace the 1/4" NPT plug in the vent hole.
6. Replace all previously removed sheet metal enclosures on the unit.
OMM-0145_D • GF-218 •
11/2/2020
5.5% ± 0.5% <100 ppm
5.5% ± 0.5% <100 ppm
5.5% ± 0.5% <100 ppm
5.5% ± 0.5% <100 ppm
6.0% ± 1.0% <100 ppm
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
<150 ppm
<150 ppm
<150 ppm
<150 ppm
<150 ppm
level up to
2
value
2
Page 68 of 213