Watts AERCO Benchmark BMK750 Operation And Service Manual page 62

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 4 – INITIAL START-UP
PROPANE Combustion Calibration Instructions
7. Verify that the incoming gas pressure to the unit is within the allowable range (see the
Benchmark Gas Supply Design Guide (TAG-0047, GF-2030).
9. Once you have completed the previous step, move the manometer (or use a secondary
one) to the downstream side of the SSOV and press Next to continue.
10. For the NOx requirement choose None.
11. The main Manual Combustion Calibration screen appears. It provides two methods to
ramp the unit's valve position up or down:
•
Method 1: Toggle through the pre-set calibration points till you reach the desired
valve position, then press Go to go to that point (left image below).
•
Method 2: Enable Fine VP Step, then manually press the + or – buttons once per
1% to bring the unit to the desired valve position (right image below).
PRE-SET CALIBRATION CONTROLS
12. Set the Controller's Enable/Disable switch to Enable.
13. Change the valve position to 30%, press the Go button, then verify that the unit has ignited
successfully and is operating as expected.
14. Use the  (Right) arrow key to change the valve position to 100%, then press Go.
15. Verify that the gas pressure on the downstream side of the SSOV is within the required
range shown in Table 4-4. If it isn't, remove the brass hex nut on the SSOV actuator to
access the gas pressure adjustment screw (Figure 4-3). Adjust using a flat-tip screwdriver,
slowly rotating the gas pressure adjustment (in 1/4-turn increments) clockwise to increase
gas pressure or counterclockwise to reduce it. The resulting gas pressure reading on the
downstream manometer should fall in the range listed below.
OMM-0145_A99 • GF-218 •
Figure 4-8: Choose NOx Requirement
Figure 4-9: Manual Combustion Calibration Screens
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
9/18/2019
VALVE POSITION CONTROLS
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