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Microaire Ovens 32Z3311e Issue 5
Procedure D - High Voltage Capacitor Test
You will need:
A Digital Multi-meter (D.M.M.)
A Megger or similar resistance meter using 500V d.c.
1 Isolate the oven from the mains supply.
2 Ensure that the High Voltage Capacitor is discharged before commencing work.
3 Remove all connections from the High Voltage Capacitor.
4 Using a D.M.M., check for continuity between the terminals & compare results with table.
5 Using a Megger, test the insulation resistance between the terminals and the case.
WARNING: High voltages and large currents are present at the High Voltage Capacitor. It is very
dangerous to work near this part when the oven is on. NEVER make any voltage
measurements at the High Voltage circuits, including the magnetron filament .
WARNING: Even when the oven is not cooking, the High Voltage Capacitor has High Voltages
present because of the Soft Start circuit. Isolate the oven before testing.
Between Terminals
Pass if approximately 10 M
Ω
Between Terminals and Case
Pass if open circuit
Between Terminals and Case
Pass if over 100 M
Ω
Procedure E - High Voltage Rectifier Test
You will need:
A Megger or similar resistance meter using 500V d.c.
1 Isolate the oven from the mains supply.
2 Ensure that the High Voltage Capacitor is discharged before commencing work.
3 Remove all connections from the High Voltage Rectifier.
WARNING: High voltages and large currents are present at the High Voltage Rectifier. It is very
dangerous to work near this part when the oven is on. NEVER make any voltage
measurements at the High Voltage circuits, including the magnetron filament .
WARNING: Even when the oven is not cooking, the High Voltage Rectifier has High Voltages
present because of the Soft Start circuit. Isolate the oven before testing.
Open Circuit both ways
FAIL
Conducts one way only
PASS
Short Circuit both ways
FAIL
Conducts one way, leaks the other
FAIL