Detailed Sequence Of Operation; Service Hints - UTICA BOILERS UB90125 Installation, Operation And Maintanance Manual

POWER ON
STAND BY
THERMOSTAT
CALLS FOR HEAT
CIRCULATOR
ENERGIZES THRU
2K1 CONTACTS
IBC SELFCHECK OF
INTERNAL CIRCUITRY
1-2 SEC
IBC
CHECKS
N.O. AIR
PRESSURE
SWITCH
CONTACTS
OPEN
DRAFT INDUCER
ENERGIZES THRU
1K1 CONTACTS
IBC
WAITS FOR
UP TO 5 MINUTES
CLOSED
FOR AIR PRESSURE
SWITCH CONTACTS TO CLOSE
INDICATING FAN
SUCTION
PRESENT
OPEN
CONTROL LOCKOUT. PURGE LIGHT BLINKS.
MANUAL RESET IS REQUIRED OR CONTROL
WILL AUTOMATICALLY RESET AFTER 15
MINUTES. CIRCULATOR REMAINS ENERGIZED
AS LONG AS THERMOSTAT CONTINUES
TO CALL FOR HEAT
PURGE LIGHT IS ON. AIRFLOW PROVED.
DRAFT INDUCER RUNS FOR 15 SEC PREPURGE

DetaileD seQUeNce oF oPeratioN

sERVIcE HInts

CLOSED AIRFLOW. IBC WAITS
FOR 45 SEC
FOR AIR PRESSURE
SWITCH CONTACTS
.
IF MAIN BURNER DOES NOT PROVE FLAME IN
3 TRIALS, CONTROL LOCKOUT. VALVE/FLAME
LIGHT BLINKS. MANUAL RESET IS REQUIRED OR
CONTROL WILL AUTOMATICALLY RESET AFTER
1 HOUR. THIS PROBLEM IS A RESULT OF NOT
ESTABLISHING A FLAME SIGNAL.
ADDITTIONAL IGNITION SEQUENCES.
FALSE
POSITIVE
PROOF OF
CLOSED
TO OPEN
OPEN
DURING THE LAST 2 SEC OF THE 5 SEC IGNITION
TRIAL MAIN BURNER FLAME IS PROVED BY FLAME
RECTIFICATION A FLAME SIGNAL TO IBC. GAS VALVE
REMAINS ENERGIZED. BOILER RUNS.
2 SEC INTO THE 5 SEC IGNITION TRIAL. POWER
IS TURNED OFF TO THE HOT SURFACE IGNITER.
IGNITER LIGHT IS 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 IS ON.
PURGE LIGHT GOES OUT. HOT SURFACE IGNITER
POWERED THRU 5K1 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, IGNITOR LIGHT IS ON
31
CONTROL WILL ATTEMPT 2
STARTING WITH PREPURGE.
NO
DOES
MAIN
BURNER PROVE
YES
FLAME WITHIN INITIAL
TRIAL FOR
IGNITION
PERIOD?
NORMAL
OPERATION