Se Uen E O Operation Flow Chart - A.O. Smith 104 Series Instruction Manual

SEQUENCE OF OPERATION FLOW CHART
Des ription of this ow hart an be found in the SEQUENCE OF OPERATION se tion found on page 25
START
SAFE
START
CHECK
VALVE-ON DELAY
(S89F ONLY)
TRIAL FOR
IGNITION
BURNER
OPERATION
END
THERMOSTAT
CALLS FOR HEAT.
SAFE START
CHECK
VALVE-ON DELAY
30S PREPURGE
COMBUSTION
AIR BLOWER STARTS.
SPARK GENERATOR
POWERED, IGNITION
BEGINS AND GAS
CONTROL OPENS.
BURNER LIGHTS.
IGNITION STOPS
AND FLAME
CURRENT IS
SENSED.
BURNER RUNS
S89 MONITORS
FLAME CURRENT.
THERMOSTAT
SATISFIED. GAS
CONTROL CLOSES,
BURNER GOES OFF.
FLOWCHART 1.
24
POWER INTERUPTION.
SYSTEM SHUTS OFF. RESTARTS
WHEN POWER IS RESTORED.
IF FLAME SIMULATION
CONDITION IS PRESENT,
SYSTEM WILL NOT START.
IF NO SPARK, S89 LOCKS OUT
AND SHUTS DOWN SYSTEM.
MUST BE RESET.
IF FLAME CURRENT IS ABSENT,
WEAK, OR UNSTEADY, S89
LOCKS OUT AND SHUTS DOWN
SYSTEM. MUST BE RESET.
IF FLAME IS LOST, S89 CLOSES
GAS CONTROL, THEN RESTARTS
SAFE START CHECK AND TRIAL
FOR IGNITION.