AERCO BMK 1.5 LN Dual Fuel June 2010 - Manual (Page 38)

INITIAL START-UP
55. Press the ▼ arrow key until CAL Voltage
16% is displayed.
56. Press the CHANGE key. CAL Voltage 16%
will begin to flash.
57. The oxygen level at the 16% valve position
should be as shown below. Also, ensure that
the carbon monoxide (CO) and nitrogen
oxide (NOx) readings do not exceed the
values shown.
Combustion Oxygen Level at
16% Valve Position
Oxygen %
± 0.2
Carbon
Monoxide NOx
8.0 % <50 ppm <30 ppm
58. If the oxygen level is not within the specified
range, adjust the level using the ▲ and ▼
arrow keys. This will adjust the output
voltage to the blower motor as indicated on
the display. Pressing the ▲ arrow key
increases the oxygen level and pressing the
▼ arrow key decreases the oxygen level.
59. Once the oxygen level is within the specified
range at 16%, press the ENTER key to store
the selected blower output voltage for the
16% valve position.
60. This completes the natural gas combustion
calibration procedure.
IMPORTANT
Refer to Appendix K for switchover
instructions when changing from Natural
Gas to Propane or from Propane to
Natural Gas.
4.4 PROPANE COMBUSTION
CALIBRATION
The Benchmark 1.5LN Dual-Fuel Boiler is
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.
It is important to perform the following procedure
as outlined. This will keep readjustments to a
minimum and provide optimum performance.
1. Open the water supply and return valves to
the unit and ensure that the system pumps
are running.
2. Open the propane 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 valve position in %. Also,
the MANUAL LED will light.
6. Adjust the valve position to 0% by pressing
the ▼ arrow key.
7. Ensure that the leak detection ball valve
down-stream of the Propane SSOV (Figure
4-1) is open.
8. Ensure that the Fuel Selector Switch (Figure
4-3) is in the PROPANE position.
9. Set the ON/OFF switch to the ON position.
10. Access the control panel Configuration
Menu and change the Max Valve Position to
70%. (Refer to Chapter 3, para. 3.3 for
instructions on changing menu options).
11. Change the valve position to 29% using the
▲ arrow key. The unit should begin its start
sequence and fire.
12. Next, increase the valve position to 70%.
Verify that the gas pressure downstream of
the Propane SSOV is 1” W.C. for both FM
and IRI gas trains. If gas pressure
adjustment is required, refer to Figure 4-7
and remove the brass hex nut on the
Propane SSOV actuator containing the gas
pressure regulator. (For IRI gas trains, the
regulator is on the downstream SSOV).
Make gas regulator adjustments using a flat-
tip screwdriver to obtain 1” W.C.
13. With the valve position at 70%, insert the
combustion analyzer probe into the vent
probe port opening (Figure 4-2) and allow
enough time for the combustion analyzer to
settle.
4-6