Sentry – Slant/Fin SENTRY SX-210 User Manual
Page 13

SEQUENCE OF OPERATION FOR SENTRY BOILERS
EQUIPPED WITH CONTINUOUS BURNING PILOTS
FOR DIAGRAMS SHOWN ON PAGE 14.
13
Sentry
LIGHTED PILOT HEATS THERMOCOUPLE AND KEEPS PILOTSTAT OPEN.
THERMOSTAT CALLS FOR HEAT
HIGH LIMIT CONTACTS CLOSED?
LOW WATER CUT-OFF (WHEN USED)
CONTACTS CLOSED?
VENT DAMPER RELAY ENERGIZED.
VENT DAMPER MOTOR OPENS VENT DAMPER.
END SWITCH CLOSES.
MAIN VALVE OPERATOR OPENS.
LIGHTED PILOT IGNITES MAIN BURNERS.
IF PILOT SHOULD BLOW OUT, THERMOCOUPLE
WILL SHUT OFF MAIN BURNER.
WHEN THERMOSTAT IS SATISFIED, OR WHEN HIGH LIMIT
OR LOW WATER CUT-OFF CONTACTS ARE OPEN, MAIN
VALVE OPERATOR CLOSES.
VENT DAMPER CLOSES. CIRCULATOR OFF.
SYSTEM GOES TO STANDBY WITH LIGHTED PILOT.
CIRCULATOR ENERGIZED
(IF COMBINATION AQUASTAT
CONTROL USED)
NO FURTHER
ACTION
SEQUENCE OF OPERATION FOR SENTRY BOILERS EQUIPPED WITH HONEYWELL INTERMITTENT
IGNITION SYSTEM (IID) FOR DIAGRAMS SHOWN ON PAGE 15.
THERMOSTAT CALLS FOR HEAT
HIGH LIMIT CONTACTS CLOSED?
LOW WATER CUT-OFF (WHEN USED)
CONTACTS CLOSED?
VENT DAMPER RELAY ENERGIZED.
VENT DAMPER MOTOR OPENS VENT DAMPER.
END SWITCH CLOSES.
IGNITION CONTROL ENERGIZED
THE PILOT FLAME ESTABLISHED ?
SPARK GENERATOR OFF. MAIN VALVE
OPERATOR OPENS. MODULE MONITORS
PILOT FLAME.
WHEN THERMOSTAT IS SATISFIED OR WHEN HIGH LIMIT OR LOW WATER CUT-OFF CONTACTS ARE OPEN, VALVE OPERA-
TORS CLOSE. PILOT & MAIN BURNERS OFF. VENT DAMPER CLOSES. CIRCULATOR OFF. SYSTEM GOES TO STANDBY.
SPARK GENERATOR MODULE POWERED.
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 & S8670E)
IGNITION TRIAL CONTINUES FOR 90 SEC-
ONDS. AFTER TRIAL FOR IGNITION, SYS-
TEM SHUTS OFF. AFTER 5 MINUTES MOD-
ULE RE-INSTATES TRIAL FOR IGNITION. IF
PILOT FLAME NOT ESTABLISHED, IGNI-
TION TRIAL, SYSTEM SHUT-OFF AND 5
MINUTES WAIT SEQUENCE REPEATS
CONTINUOUSLY.
NATURAL GAS (S8600F) IGNI-
TION SPARK CONTINUES.
PILOT VALVE REMAINS OPEN
UNTIL SYSTEM IS RESET.
CIRCULATOR ENERGIZED
(IF COMBINATION AQUASTAT
CONTROL USED)
NO FURTHER
ACTION
NO
YES
NO
YES
NO
NO
YES