Overview of Primary Product

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FUNCTION SUMMARY
Combustion Air Flow Check Terminal
The Multi-Burner Control checks that the combustion air flow switch is open before start-up, closed
during operation and open again at burner shutdown, thus preventing operation with an air switch
that is defective, maladjusted or jumped.
Main Fuel Valve Proof-of-Closure Terminal
The Multi-Burner Control checks that the main fuel valve is closed before start-up and after burner
shutdown. This arrangement requires an approved proof-of-closure switch on the main fuel valve.
Low Fire Start Terminal
The system checks for the low fire start position prior to light-off.
High Fire/High Fire Purge Check Terminal
When selected, the system checks that the air modulation motor reached the high fire position during
high fire purge. The modulation motor must be fitted with a high fire position switch, which is then
connected to the high fire check terminal. An air flow or pressure switch that is set to prove sufficient
purge air may be used instead of the high fire position switch.
Recycle Mode
When selected, the Multi-Burner Control will restart the sequence after flame or air failure. The
recycle mode allows the system to re-initiate the start-up sequence automatically, once the main
burners have been operating for at least 35 seconds. If the pilot flame fails to light during recycling,
the system will lock out and annunciate a pilot flame fail. If the recycle is successful and the main
burners are operational for at least 35 seconds, the system is ready for another recycle. At no time
will the system recycle in the event of pilot flame fail.
Pilot Test Mode
This mode is entered by depressing the “Reset” and the “Enter” buttons simultaneously then releas-
ing the “Reset” button but holding the “Enter” button for another 10 seconds. The limits light will
flash off and on, indicating that the system is in the test mode. In the pilot test mode, the Multi-
Burner Control operates normally with the exception that the main valves are not energized, prevent-
ing the main burners from igniting. To exit the pilot test mode, simply press the “Reset” button and
the Multi-Burner Control will exit the pilot test mode and restart the sequence.
Interrupted or Intermittent Pilot
Pilot mode is selected using the DIP switch (see “S2 DIP Switch Settings” on page 7). An interrupted
pilot shuts off after the main flame is established. An intermittent pilot continues during the entire
main flame firing cycle.
Spark, Pilot Flame and Main Flame Separation
During the trial for ignition period (TFI), the pilot valve and ignition coil remain energized. At the
end of the TFI, the pilot flame remains on and the ignition coil is de-energized. After a five second
delay to prove the pilot flame, the main gas valve is energized to begin the main trial for ignition.
The times selected with SW3 of S2 and SW7 of S4 apply to both pilot and main trial for ignition.
Note: All pilots must light within the specified TFI or a pilot flame failure will occur.
If one burner experiences either a pilot or main flame failure, then all burners will shut
down. The failed burner will be indicated by the red “Flame Fail” light on the correspond-
ing flame sensor, MB-600PF.