Lincoln Impinger Conveyor Ovens 1100 Series - Manual (Page 9)

SEQUENCE OF OPERATIONS 1152 thru 1158
MODEL 1152 NAT.GAS 220 VAC 50 HZ 1 PHASE
MODEL 1153 L.P. GAS 220 VAC 50 HZ 1 PHASE
MODEL 1154 NAT. GAS 240 VAC 50 HZ 1 PHASE
MODEL 1155 L.P. GAS 240 VAC 50 HZ 1 PHASE
MODEL 1156 TOWN.GAS 220/240 VAC 50 HZ 1 PHASE
MODEL 1157 NAT. GAS 220/240 VAC 50 HZ 1 PHASE
MODEL 1158 L.P. GAS 220/240 VAC 50 HZ 1 PHASE
POWER SUPPLY Electrical power to be supplied to the oven by a three conductor service.
CONTROL BOX AUTO COOL DOWN When the temperature in the Control Box reaches
120°F ± 3°F (48.9°C ± 1.7°C), the Cooling Fan Thermostat will switch
power to the Control Box Cooling Fans. The Thermostat will interrupt
power to the Cooling Fans when ‘the control box temperature falls to
100°F ± 3°F (37.8°C ± 1.7°C).
MAIN FAN CIRCUIT Power is permanently supplied to the normally open contacts of the oven
fan relay, the normally open cooling fan thermostat, and to the normally
open oven fan switch. Closing the fan switch supplies line voltage,
through a 1A fuse, to the primary of the power transformer (the trans-
former steps the voltage down to 120 VAC for the control circuit.) 120
VAC is supplied to the cooling fans, terminal #1 of the time delay relay and
to the coil of the oven start relay. These normally open contacts close
enabling the 20 minute time delay relay. The 20 minute time delay relay
supplies 120 VAC to the oven fan relay, its normally open contacts now
close, supplying line voltage to the main fan motor.
BURNER CIRCUIT Closing the Fan Switch supplies line voltage through the 3 amp fuse, and
oven start relay (closed by activating the Relay in the main fan circuit).
Closing the Burner Switch allows voltage to be supplied through the
normally open gas pressure switch(located in gas valve and closed
when proper gas pressure is present), through the normally open Air
Pressure Switch (closed by air pressure from main fan), through the
normally closed oven cavity high limit thermostat (opens at 662°F (350°C)
which is manually resetting after a 18°F(10°C) drop), and to the ignition
control.
IGNITION CONTROL The Ignition Control switches (220 or 240 VAC) to the combustion Blower
Motor, the normally open combustion Air Switch closes upon sensing air
pressure in the burner housing. After a pre-purge period of between 30
and 60 seconds, the Spark Generator is energized, the Main Gas Valve
Solenoid Valve and Burner Pilot Light are energized, and ignition should
now occur.
When the burner ignition occurs, the Flame Sensor must provide micro
amps (normally 2-4 ) to the Ignition Control within 1 second or the burner
system will shut down and the buzzer alarm will sound. To recycle the
burner, switch off the burner switch (this will disable the buzzer), wait 30
seconds, push IN the reset button for the ignition control, and turn on the
Burner Switch. The burner sequence of events should now reoccur.
TEMPERATURE CONTROL Closing the Fan Switch supplies 120 VAC to the Electronic Temperature
Control. The 2.5K ohm Temperature Potentiometer is
Impinger II - 1100 Series Service Manual - International 9