Table of Contents
Advertisement
PROCEDURES FOR PRINCIPAL COMPONENTS TEST (1)
1. Power Transformer Test
You will need:
A Digital Multi-meter (D.M.M.)
A Megger or similar resistance meter using 500V d.c.
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.
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 Power Transformer.
4
Using a D.M.M., check the resistance of the windings. Results should be as follows:
a
Mains winding between tags
b
High Voltage winding
c
Filament winding
between terminals
5
Using a Megger, test the insulation resistance between:
Primary winding and chassis
Filament winding and chassis
One end of the High Voltage winding is connected to the
chassis, so this is not tested.
2. High Voltage Capacitor Test
You will need:
A Digital Multi-meter (D.M.M.)
A Megger or similar resistance meter using 500V d.c.
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.
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 on next page.
See Safety Code ( Page 4 )
Approx. 1.1 Ω
Approx. 60 Ω
Less than 1 Ω
Pass if over 10 MΩ
Pass if over 10 MΩ
See Safety Code ( Page 4 )
Mealstream Ovens Pt. No. 32Z3403 Issue 16
Page 25
c
b
a
Advertisement
Table of Contents
