AERCO BMK 1.5 LN Dual Fuel Feb 2013 - Manual (Page 56)

CHAPTER 4: INITIAL START-UP
Page 56 of 162 PR2: 05/09/12
Benchmark 1.5LN Dual-Fuel Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0C
GF-121
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
43. Press the ▲ arrow key until SET Valve Position appears on the C-MORE display.
44. Press the
CHANGE key. SET Valve Position will begin to flash.
45. Press the ▼ arrow key until the SET Valve Position reads 30%, then press the
ENTER key.
46. Press the ▼ arrow key until CAL Voltage 16% is displayed.
47. Press the
CHANGE key. CAL Voltage 16% will begin to flash.
48. 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
8.5 % <100 ppm <30 ppm
49. 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.
50. 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.
51. This completes the Propane Combustion Calibration procedure.
4.6 UNIT REASSEMBLY
Once the combustion calibration adjustments are properly set, the unit can be reassembled
for service operation.
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.
5. Remove the combustion analyzer probe from the vent hole. Replace the NPT plug
in the vent hole using a suitable pipe joint compound.
6. Replace the unit’s side panels and front door.
4.7 OVER-TEMPERATURE LIMIT SWITCHES
The unit contains both automatic and manual reset over-temperature limit switches. These
switches are mounted on a plate as shown in Figure 4-6. The switches can be accessed by
opening the front panel door of the unit. The manual reset switch is not adjustable and is
permanently fixed at 200°F. This switch will shut down and lock out the boiler if the water
temperature exceeds 200°F. Following an over-temperature condition, it must be manually
reset by pressing the RESET button before the boiler can be restarted. The automatic
reset over-temperature switch is adjustable and allows the boiler to restart, once the
temperature drops below its temperature setting. Set the automatic over-temperature
switch to the desired setting.