Sequence of Operations

POWER SUPPLY

CONTROL BOX AUTO COOL DOWN

MAIN FAN CIRCUIT

BURNER CIRCUIT

TEMPERATURE

CONTROL

CONVEYOR DRIVE

MODEL 1456 / 220-240 VAC / 50 HZ / NATURAL GAS

MODEL 1457 / 220-240 VAC / 50 HZ / L.P. GAS

MODEL 1474 / 220-240 VAC / 50 HZ / NATURAL GAS

MODEL 1475 / 220-240 VAC / 50 HZ / L.P. GAS

MODEL 1476 / 220-240 VAC / 50 HZ / TOWN GAS

Electrical power is to be supplied to the oven by a three-conductor service. Brown conductor is hot.

Blue conductor is neutral. Green conductor is ground.

When the temperature in the control box reaches 120°F ± 3° (48.9°C ± 1.7°C), the cooling fan thermostat will switch power to the control box cooling fan. The thermostat will interrupt power to the cooling fan when the control box temperature falls to 100°F ± 3° (37.0°C ± 1.7° C).

Electrical power is permanently supplied to the normally open contacts of the double pole main fan relay, the cooling fan thermostat and, through a 3A fuse to the normally open double pole main fan switch. Closing the oven fan switch supplies line voltage to the primary of the control circuit step down transformer. The transformer steps the voltage down to 120 VAC for the control circuit. 120 VAC is supplied to the coil of the double pole main fan relay. The coil of the relay is energized. The normally open contacts now close, energizing the main fan motor through one 10A fuse, and the cooling fan motor.

Closing the oven fan switch supplies line voltage through the main fan air pressure switch, through the gas pressure proving switch, through the normally closed Hi-Limit Thermostat, to the ignition control. The combustion motor is now energized The normally open combustion air switch closes upon sensing air. After a pre-purge period of between 30 and 60 seconds, the spark generator and the main gas valve are energized. Ignition should now occur, after proving, gas control relay is energized.

Closing the oven power switch supplies 120 VAC (through the step-down transformer) to the temperature control board. The temperature dial is adjusted to desires temperature. The thermocouple will provide varying millivolts to the temperature controller. The temperature controller supplies120 VAC through contact of gas control relay to the solenoid valve at intervals to maintain desired temperature. The ready lamp is energized with the solenoid valve (an electronic flame monitor proves main flame operation in the 1474, 1475, 1476 models.)

Closing the on/off switch supplies 120 VAC (through the step down transformer) to the conveyor control board. AC volts are converted to DC volts and are supplied to the conveyor motor at terminals A+ and A-. Adjustment of the speed control potentiometer will change resistance at terminals P1 & P2 varying the DC voltage to the motor. The speed of the conveyor motor will increase or decrease as the DC voltage from the board increases or decreases respectively.

NOTE: The conveyor control uses a sensor and magnet, mounted on the conveyor motor that senses the motor speed. Any change in motor load (± RPM) is detected by the sensor and the voltage to the motor is adjusted accordingly.

Impinger I – 1400 Series Advantage Service Manual – Dom & Int’l