23
2 SEC INTO THE 5 SEC IGNITION TRIAL, POWER
IS TURNED OFF TO THE HOT SURFACE IGNITER.
IGNITER LIGHT OFF.
GAS VALVE OPENS FOR 5 SEC TRIAL FOR
IGNITION, BLUE ORANGE GLOW OF THE BURNER
CAN BE SEEN THRU OBSERVATION PORT.
GAS VALVE ENERGIZED THRU 3K1 AND 4K1.
CONTACTS. VALVE LIGHT ON.
PURGE LIGHT GOES OUT. HOT SURFACE IGNITER
POWERED THRU 5K1 AND 5K2 CONTACTS FOR 20
SEC IGNITER WARMUP. BRIGHT YELLOW
ORANGE GLOW OF THE HOT SURFACE IGNITER
CAN BE OBSERVED THRU THE OBSERVATION
PORT IN FRONT OF BOILER SECTION JUST
ABOVE IGNITER. IGNITER LIGHT ON.
DETAILED SEQUENCE OF OPERATION
CONTROL LOCKOUT. PURGE LIGHT BLINKS.
MANUAL RESET REQUIRED OR CONTROL
WILL AUTOMATICALLY RESET AFTER 15
MINUTES. CIRCULATOR REMAINS ENERGIZED
AS LONG AS THERE IS A CALL FOR HEAT
OPEN
IBC
WAITS FOR
UP TO 5 MINUTES
FOR AIR PRESSURE
SWITCH CONTACTS
TO CLOSE
INDICATING FAN
SUCTION PRESENT
CLOSED
CLOSED
OPEN
OPEN
CLOSED
YES
NO
IBC
CHECKS
N.O. AIR
PRESSURE
SWITCH
IBC SELF CHECK OF
INTERNAL CIRCUITRY
1-2 SEC
CIRCULATOR
ENERGIZES THRU
2K1 CONTACTS
THERMOSTAT
CALLS FOR HEAT
PO WER ON
STANDBY
NORMAL SEQUENCE OF OPERATION
IF MAIN BURNER DOES NOT PROVE FLAME IN 3
TRIALS, CONTROL LOCKOUT. VALVE/FLAME
LIGHT BLINKS. RESET IS REQUIRED. THIS
PROBLEM IS A RESULT OF NOT ESTABLISHING
FLAME SIGNAL.
CONTROL WILL ATTEMPT 2 ADDITIONAL
IGNITION SEQUENCES STARTING WITH
PREPURGE
CONTACTS
FALSE POSITIVE
PROOF OF
AIRFLOW. IBC WAITS
FOR 45 SEC FOR
AIR PRESSURE
SWITCH
CONTACTS TO
OPEN
NORMAL
OPERATION
DOES MAIN
BURNER
PROVE FLAME
WITHIN INITIAL
FOR IGNITION
PERIOD
DRAFT INDUCER
ENERGIZES THRU
1K1 CONTACTS
PURGE LIGHT ON. AIRFLOW APPROVED.
DRAFT INDUCER RUNS FOR 15 SEC PREPURGE
DURING THE LAST 2 SEC OF THE 5 SEC IGNITION
TRIAL, MAIN BURNER FLAME IS PROVED BY FLAME
RECTIFICATION THRU HOT SURFACE IGNITER,
PROVIDING A FLAME SIGNAL TO IBC. GAS VALVE
REMAINS ENERGIZED. BOILER RUNS.
A06101
Fig. 21
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Normal Sequence of Operation