AERCO BMK 1.5 LN July 2011 - Manual (Page 74)

CHAPTER 7: MAINTENANCE
Page 74 of 152 PR2: 05/09/12
Benchmark 1.5LN Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0D
GF-120
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
8. Reinstall the igniter-injector in the burner plate. Torque to 15 ft-lbs. Do not over tighten.
9. Connect the staged ignition assembly to the gas injector tube of the igniter-injector by
securing the compression nut to the elbow of the staged ignition assembly.
10. Reconnect the igniter-injector cable.
11. Reinstall the side and top panels on the unit.
7.3 FLAME DETECTOR
The flame detector (part no. 66006) is located on the burner plate at the top of the unit (see
Figures 7-1 and 7-2). The flame detector may be hot. Allow the unit to cool sufficiently before
removing the flame detector.
To inspect or replace the flame detector:
1. Set the
ON/OFF switch on the control panel, to the OFF position. Disconnect AC power from
the unit.
2. Remove the side and top panels from the unit.
3. Disconnect the flame detector lead wire.
4. Remove the two (2) screws securing the flame detector to the plate (Figure 7-2 on previous
page). The flame detector is secured to the burner plate with one (1) #10-32 screw and one
(1) #8-32 screw.
5. Remove the flame detector and gasket from the burner plate.
6. Thoroughly inspect the flame detector. If eroded, the detector should be replaced.
Otherwise clean the detector with a fine emery cloth.
7. Reinstall the flame detector and flame detector gasket.
8. Reconnect the flame detector lead wire.
9. Reinstall the side and top panels on the unit.
7.4 COMBUSTION CALIBRATION & RSI REGULATOR ADJUSTMENT
The Combustion Calibration settings and RSI Regulator adjustment must be checked at the
intervals shown in Table 7-1 as part of the maintenance requirements. Refer to Chapter 4 for
combustion calibration instructions. Refer to paragraph 7.4.1, below, for RSI regulator test and
calibration instructions.
RSI Regulator Pressure 7.4.1
The BMK1.5LN unit has a RSI (Regulated Staged Ignition) system in the gas train that should
be pressure tested annually. If the pressure is above 5.0” w.c. or below 3.0” w.c., then the RSI
pressure regulator must be recalibrated per paragraph 7.4.1.2.
RSI Regulator Pressure Test 7.4.1.1
The RSI regulator test is performed as follows:
1. Ensure that gas supply shut-off valve upstream of the unit is still turned OFF.
2. Turn OFF electrical power to the system.
3. CLOSE the following valves in the unit’s gas train (refer to Figure 7-4):
• RSI Gas Supply Valve
• RSI Bleed-off Valve
• Manual Shut-off Valve (between the Air/Fuel Valve and the SSOV).