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R-252M 11
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
I
MOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
terminals as described in the table below.
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately 360
Ω
Turntable motor
Approximately 12 - 15 k
Ω
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
LIVE TEST FOR MOTOR WINDING
CAUTION: The following procedure requires the oven to be connected to the supply and should
only be used if the relevant "cold" checks for the motor under test are inconclusive.
1. CARRY OUT 3D CHECKS.
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads
2. Disconnect the leads from the primary of the high voltage transformer. Make sure that the leads
remain isolated from other oven components and chassis (Use insulation tape if necessary.)
3. Connect the voltmeter, set to 250V AC, across the motor terminals. (Refer to the relevant motor test
procedure or pictorial diagram for the correct terminal numbers.)
4. Arrange the meter in a position where it can be read during the test.
(Do not touch the meter, meter leads or oven circuitry while the oven is active.)
5. Close the oven door.
6. Set the power level to HIGH and set the relevant timer for about three (3) minute.
7. Note the reading on the meter and carefully observe the motor under test to see if it is turning.
8. CARRY OUT 3D CHECKS.
9. Remove the test meter leads.
10.Reconnect the leads to the primary of the high voltage transformer.
6. Set the power level to HIGH and set the relevant timer for about three (3) minute.
7. Note the reading on the meter and carefully observe the motor under test to see if it is turning.
8. CARRY OUT 3D CHECKS.
9. Remove the test meter leads.
10.Reconnect the leads to the primary of the high voltage transformer.
If a reading of the line voltage was obtained (step 7) but the motor was not turning then it is faulty and
should be replaced. If the meter indicated that the no supply was present then the winding to the motor
should be checked for continuity.
should be replaced. If the meter indicated that the no supply was present then the winding to the motor
should be checked for continuity.
Disconnect the leads from the terminals of noise filter.
Using an ohmmeter, check between the terminals as
described in the following table.
Using an ohmmeter, check between the terminals as
described in the following table.
MEASURING POINTS
INDICATION OF OHMMETER
Between N and L
Approx. 680 k
Ω
Between terminal N and WHITE
Short circuit
Between terminal L and RED
Short circuit
If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT 4R CHECKS.
CARRY OUT 4R CHECKS.
F: FUSE
F1
N
L
0.22
µ
/AC250V
680K/ 0.5W
10M/ 0.5W
NOISE
SUPPRESSION COIL
SUPPRESSION COIL
0.0033
µ
/ 250V
0.0033
µ
/ 250V
NOISE FILTER
RED
WHT
H
NOISE FILTER TEST
CARRY OUT 3D CHECKS.
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