How To Check A Capacitor; How To Check A Magnetron For Open/Shorted Filament; How To Check A High Voltage Transformer Or Filament Transformer; High Voltage And Filament Transformer Resistance Table - TurboChef TORNADO Service Manual

How to Check a Capacitor

1. Disconnect the oven from the power source.
2. Fully discharge the capacitor.
3. Isolate the capacitor from the circuit.
4. Connect the ohmmeter between the capacitor
terminals. The ohmmeter should momentarily
indicate a low impedance and then slowly return
to infinite resistance.
5. Reverse the ohmmeter leads and repeat Step 4.
6. Check each terminal to case. Infinite resistance
(open) should be indicated.

How to Check a Magnetron for Open/Shorted Filament

1. Disconnect the AC power source and discharge
the high-voltage capacitors.
2. Isolate the magnetron from the circuit by removing
the wires from the F and FA terminals. Figure 25.

HIGH VOLTAGE AND FILAMENT TRANSFORMER RESISTANCE TABLE

HIGH VOLTAGE TRANSFORMERS
NGC-3062-1
NGC-3062-2
NGC-3062-3
FILAMENT TRANSFORMERS
NGC-3061-1
NGC-3061-2
NGC-3061-3
3. An ohmmeter connected between the filament
terminals (F, FA) should indicate a reading of
less than 1 ohm. Figure 25.
4. A continuity check between either filament
terminal and the magnetron chassis should indi-
cate an infinite resistance (open).
How to Check a High-Voltage or Filament Transformer
1. Disconnect the AC power source and discharge
the high-voltage capacitors.
2. Disconnect all the wires in question going to
the transformer.
3. Use an ohmmeter to check the impedance of the
primary and secondary winding. Refer to the
high-voltage and filament transformer table below
to determine if the transformer is OK. If the
resistance is different then the table indicates,
replace the transformer.
PRIMARY VOLTAGE, FREQ, TAPS,
AND RESISTANCE
208 VAC, 60 Hz, 1 & 2,
W
0.819–1.001
240 VAC, 60 Hz, 1 & 3,
W
0.972–1.188
230 VAC, 50 Hz, 1 & 2,
W
0.972–1.188
200 VAC, 50/60 Hz, 1 & 2,
W
0.784–0.958
PRIMARY VOLTAGE, FREQ, TAPS,
AND RESISTANCE
208 VAC, 60 Hz, 1 & 2,
W
17.49–21.37
240 VAC, 60 Hz, 1 & 3,
W
20.61–25.19
230 VAC, 50 Hz, 1 & 2,
W
18.99–23.21
200 VAC, 50/60 Hz, 1 & 2,
W
15.70–19.18
THE MICROWAVE SYSTEM
SECONDARY TAPS AND
RESISTANCE
4, Ground, 53.60–65.52
3, Ground, 57.52–70.30
3, Ground, 55.75–68.13
SECONDARY TAPS AND
RESISTANCE
4, 5, very low resistance - if read-
ing is open, transformer has failed.
3, 4, very low resistance - if read-
ing is open, transformer has failed.
3, 4, very low resistance - if read-
ing is open, transformer has failed.
33
W
W
W