Turbo Chef Technologies Residential Single and Double Wall Oven service manual No Heat

6.12TROUBLESHOOTING

Heater Element, Speedcook Oven

Remove the wire connections and apply the probes of an ohmmeter to each element’s respective termi- nals. The resistance should register 23 ohms for a

240 VAC unit and 17.0 ohms for a 208 VAC unit. If extreme resistance (a variance above 10%) is detected the element is faulty and needs to be replaced. En- sure that the elements are at room temperature. The temperature of the elements will change the heater’s resistance.

No Heat

1.Turn the CookWheel to Bake to activate the preheating process. The oven should immediately make an audible ‘click’ when the K9 relay closes. Wait 2-3 minutes and the oven should heat noticeably. If no heat is present, pull the oven out 11” (280 mm) to access the front half of the upper electrical compartment.

2.Check the high limit switch. Press the red button to reset the switch. If the oven is still not heating, verify L1 (brown wires) and L2 (blue wires) power is reaching the heater elements.

3.Turn the CookWheel to off, then disconnect the three top brown wires from the high limit switch and turn the CookWheel to Bake.

4.Apply the probes of the voltmeter to each of the exposed female wire terminals and to ground. If any of the terminals do not register 120 VAC, check the breaker for a partial or full trip.

5.If the high limit switch is functioning properly, apply one probe to any one of the exposed female wire terminals and keep it there. Apply the other probe to the three male terminals on the high limit switch in sequence. At least one of the three readings should register 240 VAC if the oven is heating (if this is the case, go to Oven is Heating Up Very Slowly, adjacent).

6.If none of the elements are receiving 240 VAC, test the K9 relay, then the K1 and K8 relays (Gen 1) or K1 and relay 14 on the relay board

(Gen 2) to verify both are receiving control voltage from the control board.

Oven is Heating up Very Slowly

1.Turn the CookWheel to Bake to begin preheating. The oven should immediately make an audible ‘click’ when the K9 relay closes.

2.After 2-3 minutes, the oven should heat noticeably. If little heat is present, pull the oven 11” (280 mm) from the cabinet to access the front half of the upper electrical compartment.

NOTE: If the oven is heating, the K9 relay is functioning because it is the single source of L2 voltage to all three elements. Therefore, testing should begin with L1 voltage reaching the elements.

3.Turn the CookWheel to off, then disconnect the three top brown wires from the high limit switch.

4.Turn the CookWheel to Bake.

5.Apply one probe of the voltmeter to any one of the exposed female wire terminals and keep it there. Apply the other probe to the three male terminals on the high limit switch in sequence. At least one of the three readings should register 240 VAC if the oven is heating at all.

6.If either of the primary elements is not receiving 240 VAC, test the K1 SSR to verify it is receiving voltage from the control board to activate.

7.If the preheat element is not receiving 240 VAC:

-Gen 1: Test the K8 relay for 24 VDC from the control board to activate.

-Gen 2: Test relay 14 for 9 amps on the relay board at RBJ10 and RBJ11.

Testing for Control Voltage to the K1 SSR

DANGER: A high-voltage capacitor is located near this relay. Contact with the high-voltage capacitor could result in serious injury or death.

1.Turn the CookWheel to Bake to begin the preheat cycle.

2.For Gen 1 ovens, apply the voltmeter probes to P7-3 and P8-15, then to P7-3 and P8-16 (on the control board). For Gen 2 ovens, apply the voltmeter probes to RBJ22-7 and RBJ22-1, RBJ22-7 and RBJ22-2 (on relay board). T ehvoltage reading for each should be 24 VDC. If 24 VDC is present, the relay is receiving voltage.