Turbo Chef Technologies Residential Single and Double Wall Oven Heating System, Speedcook Oven

3.Disconnect the diode from the circuit.

4.Set the voltage meter to DC voltage and connect it in series with the diode and a 9-volt battery.

5.Connect one meter lead to one side of a 9-volt battery and the other lead to one side of the diode.

6.Connect the other side of the 9-volt battery to the other side of the diode. DC voltage should only be present on the meter in one direction.

7.Switch the meter leads on the diode, which will cause the opposite reading to be visible. voltage between 5-7 VDC should be present in only one direction and 0-0.1 VDC in the other direction, depending on the battery voltage.

Testing a High-Voltage Transformer

DANGER: Before replacing the transformer, ensure the oven is removed from any power source. Replacing this component while the oven is plugged in can result in serious injury or death.

DANGER: Never attempt to measure the secondary voltage values of the transformers when they are enabled. Lethal voltage will be present.

1.Disconnect the power source and discharge the high-voltage capacitors.

2.Disconnect all the wires on the transformer.

3.Use an ohmmeter to check primary winding, secondary winding, and filament.

-Primary Side

240 VAC: Taps 1&3 = 1.4 Ω

208 VAC: Taps 1&2 = 1.2 Ω

-Secondary Side

240 & 208 VAC: Tap 4&Casing = 70.1 Ω

-Filament

240 & 208 VAC: Red Wires = 0.1 Ω

Testing a Magnetron for an Open/Shorted Filament

DANGER: The only safe way to test a magnetron is by a resistance test of its filament. Never attempt to measure the magnetron using any other method while the microwave system is on. Death or serious injury could occur.

1.Disconnect the power source and discharge the high-voltage capacitors.

2.Isolate the magnetron from the circuit by removing the wires from terminals F and FA.

3.An ohmmeter connected between the filament terminals (F, FA) should indicate a reading of less than 1 ohm.

4.A continuity check between either filament terminal and the magnetron chassis should indicate an infinite resistance (open).

CAUTION: Be careful to not allow debris into the waveguides when servicing the magnetrons.

Heating System, Speedcook Oven

The Speedcook oven heating elements require 208- 240 VAC to operate.

NOTE: The elements are voltage specific and cannot operate properly without the correct voltage applied. Confirm incoming voltage matches the oven’s specifications (listed on the serial plate behind the oven door).

When the CookWheel is turned to any of the seven cooking cycles (except Favorites), the control board sends voltage to activate the relays, which supply power to the heating elements. L1 voltage for the two primary elements are supplied through the K1 SSR and the L1 voltage for the preheat element is supplied through the K8 relay (Gen 1) or preheat relay 14 (Gen 2 relay board). The L2 voltage for all three elements is supplied from the N.O. contact on the K9 relay.

If the oven is not heating normally, see the below troubleshooting options and use the one that best describes the situation.

This section contains information on the following topics:

-Heater element, Speedcook oven

-No heat

-Oven is heating up very slowly

-Testing for control voltage to the K1 SSR

-Testing for control voltage to the K8 relay (Gen 1)

-Testing relay 14, preheat (Gen 2)

-Testing for a K9 relay that is stuck open

-Testing for a K1 SSR that is stuck open

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TROUBLESHOOTING