AERCO BMK 1.5 LN July 2011 - Manual (Page 67)

CHAPTER 6: SAFETY DEVICE TESTING
PR2: 05/09/12 Page 67 of 152
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
6.8 AIR FLOW FAULT TESTS
These tests check the operation of the Blower Proof Switch and Blocked Inlet Switch shown in
Figure 6-3.
1. Disable the blower output drive voltage as follows:
(a) Press the MENU key until CONFIGUR-ATION MENU is displayed.
(b) Press the ▲ arrow key until the ANA-LOG OUTPUT function is displayed, then press the
CHANGE key.
(c) Press the ▼ arrow key until OFF is displayed, then press the ENTER key.
2. Start the unit in the Manual Mode at a valve position between 25% and 30%.
3. The unit should shut down and execute an IGNITION RETRY cycle by performing the
following steps:
(a) The unit will execute a 30 second re-ignition delay and display WAIT RETRY PAUSE.
(b) The unit will then execute a standard ignition sequence and display WAIT IGNITION RETRY.
4. The unit should perform one IGNITION RETRY cycle and then shut down, since the blower
is disabled. The unit will then display AIRFLOW FAULT DURING PURGE.
5. Re-enable the blower output drive voltage by performing the following steps:
(a) Press the MENU key until CONFIGUR-ATION MENU is displayed.
(b) Press the ▲ arrow key until the ANA-LOG OUTPUT function is displayed, then press the
CHANGE key.
(c) Press the ▲ arrow key until VALVE POSITION 0-10V is displayed, then press the ENTER key.
6. Once the unit has proved flame, turn off the blower by going to the Configuration Menu,
Analog Output menu item and select OFF.
7. The Blower Proof Switch will open and the blower should stop. The unit should shut down
and display AIRFLOW FAULT DURING RUN.
8. Go to the Configuration Menu, Analog Output item and select VALVE POSITION 0-10v.
9. Press the
CLEAR button. The unit should restart.
10. Next, check the Blocked Inlet Switch by first noting the current position of the Iris Air
Damper and then closing the Damper to position 8.
11. .The unit should shut down and again display AIRFLOW FAULT DURING RUN.
12. Return the Iris Air Damper to its previous setting.
13. Press the
CLEAR button. The unit should restart.
6.9 SSOV PROOF OF CLOSURE SWITCH
The SSOV shown in Figure 6-1 contains the proof of closure switch. The proof of closure switch
circuit is checked as follows:
1. Set the unit’s
ON/OFF switch to the OFF position.
2. Place the unit in Manual Mode and set the valve position between 25% and 30%
3. Refer to Figure 6-1 and locate the SSOV.