AERCO BMK 2.0 LN Natural Gas (SN G-11-1861 and above) - Manual (Page 73)

GF-123
Benchmark 2.0LN Low NOx Boiler
Chapter 6
OMM-0046_0E I nstallation, Operation and Maintenance Manual Safety Device Tests
PR1 08/20/12 AERCO International Inc.● 100 Oritani Dr. ● Blauvelt, NY 10913. ● Ph: 800-526-0288 Page 73 of 170
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 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. Remove the 1/4“ plug from the ball valve at the low gas pressure switch shown in the lower
portion of Figure 6-1.
2. Install a 0 – 16 “ W.C. manometer or a W.C. gauge where the 1/4" plug was removed.
3. Slowly open the ball valve near the low gas pressure switch.
4. Place the unit in Manual Mode and adjust the air/fuel valve position (% open) between 25
and 30%.
5. While the unit is firing, slowly close the external manual gas shut-off valve.
6. The unit should shut down and display a LOW GAS PRESSURE fault message at
approximately 2.6” W.C. The FAULT indicator should also start flashing.