AERCO BMK 1.5 LN Dual Fuel Feb 2013 - Manual (Page 41)

CHAPTER 3: CONTROL PANEL OPERATION
PR2: 05/09/12 Page 41 of 162
Benchmark 1.5LN Dual-Fuel Low NOx Boiler
Operation and Maintenance Manual
OMM-0041_0C
GF-121
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
25
TO BLOWER
AIR IN
DIAL
(DETAIL “A”)
STEPPER
MOTOR
DETAIL “A”
Figure 3-6: Air/Fuel Valve In Ignition Position
6. Up to 7 seconds will be allowed for ignition to be detected. The igniter relay will be
turned off one second after flame is detected.
7. After 2 seconds of continuous flame, Flame Proven will be displayed and the flame
strength will be indicated. After 5 seconds, the current date and time will be displayed
in place of the flame strength.
8. With the unit firing properly, it will be controlled by the temperature controller circuitry.
The boiler’s VALVE POSITION will be continuously displayed on the front panel
bargraph.
Once the demand for heat has been satisfied, the Control Box will turn off the dual SSOV
gas valves. The blower relay will be deactivated and the Air/Fuel Valve will be closed.
Standby will be displayed.
3.10 START/STOP LEVELS
The start and stop levels are the Air/Fuel Valve positions (% open) that start and stop the
unit, based on load. These levels are Factory preset as follows:
Start Level: 20%
Stop Level: 16%
Normally, these settings should not require adjustment.
Note that the energy input of the boiler is not linearly related to the Air/Fuel Valve position.
Refer to Table 3-7 for the relationship between the energy input and Air/Fuel Valve position
for a unit running on natural gas.