Troubleshooting; Operational Sequence; Gas Convection Oven - Lang Purple Product Manual

OPERATIONAL SEQUENCE

GAS CONVECTION OVEN

1.) Power switch turned on.
Power to oven light switch.
120 volts to rows A and B of 24 pin terminal block.
120/24 volt transformer energized.
24 volts to rows C and D of 24 pin terminal block.
24 volts to center connector of Back-up toggle switch.
24 volts to pin A on Back-up relay coil.
24 volts to connectors 6 and GR on spark module.
2.) Spark module begins sparking at pilot burner
24 volts to pilot valve coil of combination gas valve (Grn #33 (which jumps to main valve coil) and
Blu # 32).
Pilot valve opens.
Gas flows to pilot burner.
Pilot burner lights.
3.) Pilot light confirmed by spark module
12 to 13 micro amps on pin 4 of spark module
24 volts from pin 3 (Brn # 34A) on spark module to center connector of Back-up toggle switch.
4a). Back-up toggle switch Off
Circuit 1
24 volts to line terminal of control panel.
24 volts from switch panel (Blu # 13) 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 terminal B on Back-up relay.
Back-up relay closes, energizing 120/12 volt transformer.
12 volts to top connector on microprocessor.
Computer starts.
Product selected on Control Panel.
24 volts from Control Panel (Red # 26) 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.

TROUBLESHOOTING

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