20
Midco International Inc.
8471 95
Part 2 Service - SCEBM-1 Module 24V
XII Burner Sequence
of Operation
for 24V Burners
For 24V Models: Intermittent
Chart 6 - 24V Sequence of Operation
END
45 or earlier
30
31
0
Time Line in Seconds
Call for Heat/Burner is Energized
Sequence initialized
• Pre-purging electronics initialized
• Blower receives power
Pre-purging sequence initialized
• SCEBM-1 Control will
fl
ash red
• Blower accelerates to high speed
• Low pressure air switch is closed
Pre-purging
• Blower achieved high speed
• High pressure air switch is closed
• Honeywell S8760J is initialized and begins 30 second pre-purge
Pilot initialization
• Honeywell S8760J initializes pilot
fl
ame for 15 second trial for ignition
• Pilot valve opened and spark initialized
• SCEBM-1 Control will shine solid red
• Blower decelerate to lowest speed
Did the pilot
fl
ame light?
• Lockout
• Blower accelerates to highest speed
• Burner must be de-energized and be
re-energized in order to re-try ignition
• SCEBM-1 Control LED Light will
fl
ash
red
Lighting the main
fl
ame
• Honeywell S8760J initializes main valve
• Main
fl
ame established at low
fi
re
• SCEBM-1 Control will shine solid green if DC signal is above 2 DCV
• Burner begins modulating based on 2-10 VDC modulating signal
Heat Satis
fi
ed
• Operating control opens
• All components shut o
ff
Yes
No
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