Sequence Of Operations - Sentry S-34 Installation And Operating Instructions Manual

12
SEQUENCE OF OPERATION FOR SENTRY BOILERS
CIRCULATOR ENERGIZED
S8600F OR S8600M: IGNITION SPARK STARTS AND PILOT VALVE OPERATOR OPENS.
S8670E: IGNITION SPARK AND PILOT VALVE OPERATOR DELAYED FOR 30 70 SECONDS.
L.P . PROPANE GAS (S8600M and
S8670E) IGNITION TRIAL CONTINUES
FOR 90 SECONDS. AFTER TRIAL FOR
IGNITION, SYSTEM SHUTS OFF. AFTER
5 MINUTES MODULE RE INSTATES
TRIAL FOR IGNITION. IF PILOT FLAME
NOT ESTABLISHED, IGNITION TRIAL,
SYSTEM SHUT OFF AND 5 MINUTES
WAIT SEQUENCE REPEATS CONTINU
OUSLY.
WHEN THERMOSTAT IS SATISFIED OR WHEN HIGH LIMIT OR LOW WATER CUT OFF CONTACTS ARE OPEN, VALVE OPERATORS
CLOSE. PILOT and MAIN BURNERS OFF. VENT DAMPER CLOSES. CIRCULATOR OFF. SYSTEM GOES TO STANDBY.
THERMOSTAT CALLS FOR HEAT
HIGH LIMIT CONTACTS CLOSED?
LOW WATER CUT OFF
CONTACTS CLOSED?
YES
VENT DAMPER RELAY ENERGIZED.
VENT DAMPER MOTOR OPENS VENT DAMPER.
END SWITCH CLOSES.
IGNITION CONTROL ENERGIZED
SPARK GENERATOR MODULE POWERED.
NO
THE PILOT FLAME ESTABLISHED ?
YES
SPARK GENERATOR OFF. MAIN VALVE
OPERATOR OPENS. MODULE MONITORS
PILOT FLAME.
NO
NO FURTHER
ACTION
NATURAL GAS (S8600F) IGNI
NO
TION SPARK CONTINUES. PILOT
VALVE REMAINS OPEN UNTIL
SYSTEM IS RESET.
Sentry