CHAPTER 6: SAFETY DEVICE TESTING
Page
68
of
158
PR2: 04/22/13
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
DELAYED INTERLOCK
6.8.2
1. Remove the cover from the I/O Box and locate the DELAYED INTL’K IN terminals.
2. Start the unit in the Manual Mode at a valve position between 25% and 30%.
3. If there is a jumper across the DELAYED INTL’K IN terminals, remove one side of the
jumper. If the interlock is connected to a proving switch of an external device, disconnect
one of the wires leading to the proving switch.
4. The unit should shut down and display a DELAYED INTERLOCK OPEN fault message.
The FAULT LED should be flashing.
5. Reconnect the wire or jumper removed in step 3 to restore the interlock.
6. Press the CLEAR button to reset the fault.
7. The unit should start.
6.9 FLAME FAULT TESTS
Flame faults can occur during ignition or while the unit is already running. To simulate each of
these fault conditions, proceed as follows:
1. Set the
ON/OFF
switch to the
OFF
position.
2. Place the unit in the Manual Mode and set the valve position to 34%.
3. Close the manual gas shutoff valve located between the Safety Shut-Off Valves
(SSOVs) and the Air/Fuel Valve (see Figure 6-3).
4. Set the
ON/OFF
switch to the
ON
position to start the unit.
5. The unit should shut down after reaching the Ignition cycle and display
FLAME LOSS
DURING IGN.
6. Open the valve previously closed in step 3 and press the
CLEAR
button.
7. Restart the unit and allow it to prove flame.
8. Once flame is proven, close the manual gas valve located between the SSOV and the
Air/Fuel Valve.
9. The unit should shut down and execute an
IGNITION RETRY
cycle by performing the
following steps:
a) The unit will execute a shutdown purge cycle for a period of 15 seconds and
display
WAIT FAULT PURGE
.
b) The unit will execute a 30 second re-ignition delay and display
WAIT RETRY
PAUSE.
c) The unit will then execute a standard ignition sequence and display
WAIT
IGNITION RETRY
.
10. Since the manual gas shutoff valve is still closed, the unit will fail the ignition retry
sequence. Therefore, it will shut down and display
FLAME LOSS DURING IGNITION
following the failed
IGNITION RETRY
cycle.
11. Open the valve previously closed in step 8.
12. Press the
CLEAR
button. The unit should restart and fire.
