AERCO BMK 2.0 LN Dual Fuel Serial G-11-2402 and UP - Manual (Page 63)

PR2: 04/22/13 Page 63 of 160
Benchmark 2.0LN Dual-Fuel Low NOx Boiler
Operation and Maintenance Manual
OMM-0052_0E
GF-127
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
CHAPTER 6: SAFETY DEVICE TESTING
6.1 TESTING OF SAFETY DEVICES
Periodic safety device testing is required to ensure that the control system and safety devices
are operating properly. The boiler control system comprehensively monitors all combustion-
related safety devices before, during and after the start sequence. The following tests check to
ensure that the system is operating as designed.
Operating controls and safety devices should be tested on a regular basis or following service or
replacement. All testing must conform to local codes such as ASME CSD-1.
NOTE
MANUAL and AUTO modes of operation are required to perform the
following tests. For a complete explanation of these modes, see Chapter
3.
NOTE
It will be necessary to remove the front door and side panels from the
unit to perform the following tests.
WARNING!
ELECTRICAL VOLTAGES IN THIS SYSTEM MAY INCLUDE 120 AND
24 VOLTS AC. POWER MUST BE REMOVED PRIOR TO
PERFORMING WIRE REMOVAL OR OTHER TEST PROCEDURES
THAT CAN RESULT IN ELECTRICAL SHOCK.
6.2 NATURAL GAS LOW GAS PRESSURE FAULT TEST
Refer to Figure 6-1 and ensure that the leak detection ball valve located at the high gas
pressure switch is closed.
1. Ensure that the Fuel Selector Switch (Figure 6-2) is set to the NATURAL GAS position.
2. Remove the 1/4“ plug from the ball valve at the natural gas low gas pressure switch shown
in Figure 6-1.
3. Install a 0 – 16“ W.C. manometer or a W.C. gauge where the 1/4" plug was removed.
4. Slowly open the ball valve near the natural gas low gas pressure switch.
5. Place the unit in Manual Mode and adjust the valve position to 34%.
6. While the unit is firing, slowly close the external manual gas shut-off valve.
7. The unit should shut down and display a LOW GAS PRESSURE fault message at
approximately 8.5” W.C. The FAULT indicator should also start flashing.
8. Fully open the external manual gas shut-off valve and press the CLEAR button on the
Control Box.
9. The fault message should clear and the FAULT indicator should go off. The unit should
restart.
10. Upon test completion, close the ball valve and remove the manometer. Replace the 1/4“
plug removed in step 2.