Test Procedure - Electrolux MC1751E Service Manual

PROCEDURE
LETTER
A
MAGNETRON TEST
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED
TOOL WHILE THE OVEN IS IN OPERATION.
CARRY OUT 3D CHECK
Isolate the magnetron from high voltage circuit by removing all leads connected to the
filament terminal.
To test for an open circuit filament use an ohmmeter to make a continuity test between
the magnetron filament terminals, the meter should show a reading of less than 1 ohm.
To test for a short circuit filament to anode condition, connect ohmmeter between one
of the filament terminals and the case of the magnetron (ground). This test should be
indicated an infinite resistance.
If a low or zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER (IEC-60705-1988)
The following test procedure should be carried out with the microwave oven in a fully
assembled condition (outer case fitted). Microwave output power from the magnetron
can be measured by way of IEC 60705. To measure the microwave output power in the
microwave oven, the relation of calorie and
watt is used. When P(W) heating works for t(second), approximately
P x t/4.187 calorie is generated. On the other hand, if the temperature of the water with
V(ml) rises ∆T (°C) during this microwave heating period, the calorie of the water is V x
∆T.
The formula is as follows;
Our condition for water load is as follows:
Room temperature..............around 20°C
Power supply Voltage.........Rated voltage
Water load.........1000 g
Initial temperature...........10 ± 2°C
Heating time....52 + 3 = 55 sec.
P = 80 x ∆T
Measuring condition:
1. Container
mm.
2. Temperature of the oven and vessel
the test.
3. Temperature of the water
4. Select the initial and final water temperature so that the maximum difference
5. Select stirring devices and measuring instruments in order to minimize
removal of heat.
6. The graduation of the thermometer must be scaled by 0.1°C at minimum and an
accurate thermometer.
7. The water load must be (1000 ± 5) g.
8. "t" is measured while the microwave generator is operating at full power.
SOI 01.05 FV
TEST PROCEDURES
P x t / 4.187 = V x ∆
The water container must be a cylindrical borosilicate glass vessel having a
maximum material thickness of 3 mm and an outside diameter of approximately 190
The oven and the empty vessel are at ambient temperature prior to the start
The initial temperature of the water is (10 ± 2)°C.
between the final water temperature and the ambient temperature is 5K.
Magnetron filament heat-up time is not included.
TEST PROCEDURES
COMPONENT TEST
T P (W) = 4.187 x V x ∆T / t
14/33
of
addition or
599 36 78-06