All installations and services must be performed by qualified service personnel.
30
VI. STARTING THE UNIT
FLAME MUST BE
DETECTED WITHIN
4 SECONDS IF FLAME
IS DETECTED, THE
DELAY-TO-FAN-ON
TIME BEGINS (45 SECONDS)
IF FLAME IS NOT
DETECTED, THE GAS VALVE
IS DE-ENERGIZED, THE
IGNITOR IS TURNED OFF AND
THE CONTROL BOARD CONTROL
GOES INTO "RETRY" SEQUENCE
POWER IS APPLIED TO
THE SILICON NITRIDE
IGNITOR. IGNITOR
WARM-UP IS 20 SECONDS
POWER INTERRUPTION
SYSTEM SHUTS OFF,
RESTARTS WHEN
POWER IS RESTORED.
PRESSURE SWITCH SENSES
ADEQUATE DIFFERENTIAL
PRESSURE CONTACTS CLOSE
THERMOSTAT CALLS FOR
HEAT, CONTACTS CLOSE
CONTROL BOARD ENERGIZED,
INDUCER ENERGIZED
CONTINUOUS SAFE OPERATION CHECK IF FLAME
SIMULATION CONDITION PRESENT OR ROLL-OUT
SWITCH OPENS, SYSTEM ENERGIZES INDUCER
FAN FOR 15 SECONDS AND CIRCULATOR BLOWER
AT HEATING SPEED UNTIL SITUATION CORRECTION
AT ANY TIME THE
GAS VALVE IS
NOT ENERGIZED
A. SEQUENCE OF OPERATIONS
START TRIAL
FOR IGNITION
START
AFTER IGNITOR WARM-UP,
THE GAS VALVE IS
ENERGIZED TO OPEN
