69-1059
11
SV9540; SV9640 SmartValve™ SYSTEM CONTROLS
The system should be replaced if:
•
It does not perform properly on checkout or trouble-
shooting.
•
The gas control is likely to have operated for more than
200,000 cycles.
•
The control is wet or looks as if it has been wet.
SERVICE
WARNING
FIRE OR EXPLOSION HAZARD
CAN CAUSE PROPERTY DAMAGE,
SEVERE INJURY OR DEATH
Do not disassemble the ignition system control; it
contains no replaceable components. Attempted
disassembly or repair can damage the ignition
system control.
CAUTION
1.
Do not apply a jumper across or short any of
the terminals in the SV9540; SV9640 wiring
harness. Doing so can damage the system
transformer or the system control.
2.
After servicing, verify proper system operation.
IMPORTANT
Allow 60 seconds after shutdown before re-
energizing step-opening model to assure lightoff
at step pressure.
Sequence of Operation
1. Make sure the ignition system control switch is in the
ON position.
2. Follow the sequence of operation as shown in
Fig. 12.
THERMOSTAT CALLS FOR HEAT
AIR PROVING SWITCH PROVED
OPEN?
COMBUSTION AIR BLOWER ON
PILOT VALVE OPENS;
IGNITER POWERED
PILOT LIGHTS AND FLAME IS
SENSED DURING TRIAL
FOR IGNITION?
CIRCULATING AIR FAN ON
AFTER DELAY
MAIN VALVE OPENS;
IGNITER OFF
FLAME SENSE LOST?
THERMOSTAT CALL FOR
HEAT ENDS
FIVE-MINUTE WAIT PERIOD
WAIT FOR AIR PROVING
SWITCH TO OPEN
FLAME SENSE LOST MORE
THAN FIVE TIMES IN THIS CALL
FOR HEAT?
PREPURGE
AIR PROVING SWITCH PROVED
CLOSED WITHIN 30 SECONDS?
COMBUSTION AIR BLOWER OFF
PILOT VALVE CLOSES;
PILOT IGNITER OFF
COMBUSTION AIR BLOWER
OFF AFTER POST PURGE
PILOT AND MAIN VALVES CLOSE
COMBUSTION AIR BLOWER OFF
AFTER POST PURGE
CIRCULATING AIR FAN OFF
AFTER DELAY
WAIT FOR NEXT CALL FOR HEAT
THREE-SECOND FLAME
FAILURE RECYCLE DELAY
NO
YES
YES
YES
NO
NO
PILOT AND MAIN VALVES
CLOSE
YES
NO
YES
NO
M12234
SV9540; SV9640 INTERMITTENT PILOT SmartValve™
SYSTEM CONTROL SEQUENCE OF OPERATION
WITH ST9160 ELECTRONIC FAN TIMER OR 208907 TERMINAL BOARD
2
1
2
CIRCULATING AIR FAN OFF
AFTER DELAY
2
1
2
IGNITER TURNS OFF ABOUT 30 SECONDS INTO THE TRIAL FOR IGNITION
IF THE PILOT FLAME HAS NOT LIT. IT TURNS BACK ON FOR THE FINAL
30 SECONDS OF THE 90 SECOND TRIAL FOR IGNITION. THE PILOT VALVE
IS ENERGIZED DURING THE ENTIRE TRIAL FOR IGNITION. THIS IS NORMAL
OPERATION FOR THIS GAS IGNITION SYSTEM.
THIS FUNCTION OCCURS ONLY WITH ST9160 CONNECTED TO SmartValve™
SYSTEM CONTROL.
POWER APPLIED TO APPLIANCE
Fig. 12. SV9540; SV9640 sequence of operation.
