AERCO BMK 3.0 LN Natural Gas July 2011 - Manual (Page 32)

CONTROL PANEL OPERATING PROCEDURES
3-8
3.7 TUNING MENU
The Tuning Menu items in Table 3-5 are Factory
set for each individual unit. Do not change
these menu entries unless specifically requested
to do so by Factory-Trained personnel.
3.8 COMBUSTION CAL MENU
The Combustion Cal (Calibration) Menu items in
Table 3-6 are used to vary the speed of the
unit’s blower motor based on air temperature
and air density at prescribed Air/Fuel Valve
positions (% open). This is accomplished by
providing a DC drive voltage to the motor which
adjusts the rotational speed of the blower to
maximize combustion efficiency and ensure the
unit conforms to the Nitrogen Oxide (NOx) and
Carbon Monoxide (CO) emissions specified in
Chapter 4. The firing rates (%) and default drive
voltages are listed in Table 3-6.
Table 3-5. Tuning Menu
Available Choices or Limits
Menu Item Display Minimum Maximum Default
Prop Band 1°F 120°F 70°F
Integral Gain 0.00 2.00 1.00
Derivative Time 0.0 min 2.00 min 0.00 min
Reset Defaults? Yes, No, Are You Sure? No
Table 3-6. Combustion Cal Menu
Available Choices or Limits
Menu Item Display Minimum Maximum Default
CAL Voltage 14% .25 8.20 1.80v
CAL Voltage 30% .25 8.20 3.20v
CAL Voltage 45% .25 8.20 3.70v
CAL Voltage 50% .25 8.20 3.80
CAL Voltage 70% .25 8.20 4.60
CAL Voltage 100% .25 8.20 6.00
SET Valve Position 0% 100% 0%
Blower Output Monitor Blower Output Voltage .00
3.9 START SEQUENCE
When the Control Box ON/OFF switch is set to
the ON position, it checks all pre-purge safety
switches to ensure they are closed. These
switches include:
•
Safety Shut-Off Valve Proof of Closure
(POC) switch
• Low Water Level switch
• High Water Temperature switch
• High Gas Pressure switch
• Low Gas Pressure switch
• Blower Proof switch
• Blocked Inlet Switch
If all of the above switches are closed, the
READY light above the ON/OFF switch will light
and the unit will be in the Standby mode.
When there is a demand for heat, the following
events will occur:
NOTE
If any of the Pre-Purge safety device
switches are open, the appropriate fault
message will be displayed. Also, the
appropriate fault messages will be displayed
throughout the start sequence, if the
required conditions are not observed.
1. The
DEMAND LED status indicator will light.