Troubleshooting; Electric Convection Oven - Lang Purple Product Manual

4b). Back-up toggle switch On
Circuit 1
24 volts (Blu # 12) through door switch to motor contactor coil.
Motor contactor closes, door switch closed, motor starts.
Motor centrifugal switch closes (for heat circuit).
Circuit 2
24 Volts to Back-up thermostat.
Temperature set on Back-up thermostat
24 volts from Back-up thermostat (Red # 21B) through safety thermostat, through motor
centrifugal switch, to main valve coil of gas combination valve.
Main valve opens.
Gas flows to main burners.
Main burners light.

ELECTRIC CONVECTION OVEN

1.) Power switch turned on
Power to oven light switch.
208/240 volts to rows A and B of 24 pin terminal block.
240/208 to Line 3 points of motor contactor.
208/240 volts to terminal 1 on coil of Back-up relay.
240/24 volt transformer energized.
240/12 volt transformer energized.
24 volts to rows C and D of 24 pin terminal block.
24 volts through door switch to terminal 1 on coil of motor contactor.
24 volts to common connectors on Back-up relay.
12 volts to terminal 1 on microprocessor.
12 volts to center connector 1 of Back-up toggle switch.
208/240 volts to center connector 2 of Back-up toggle switch.
Reset circuit between power toggle switch and bottom of control panel closed (see page 9).
2A.) Back-up toggle switch Off
24 volts input to connector on control panel (see page 9).
12 volts to terminal 2 on microprocessor (see page 9).
Computer starts
Output from control panel to terminal 2 on coil of motor contactor (see page 9).
Motor contactor closes.
Motor starts.
24 volts through motor contactor points (from jumper on coil) to terminal 1 on coil of heat
contactor.
Product selected on control panel
24 volts from control panel through Hi-limit thermostat to terminal 2 on coil of heat contactor
(see page 9).
Heat contactor closes.
208/240 volts to elements.
2B.) Back-up toggle switch On
208/240 volts to ternimal 2 on coil of Back-up relay.

TROUBLESHOOTING

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