Bldc Motor - Bosch WAT28400 Repair Instructions

Test
5.2

BLDC motor

The BLDC motor is rarely defective!
A defect is very rare due to the high wear resistance of the BLDC
motor. The motor bearing is the only wear part of the motor.
When the appliance is switched on, the motor module checks
functioning of the module and motor. If there is a malfunction, a
fault display will appear.
No replacement of BLDC motor with the following fault
profiles:
• Fault display E 52, E 57, E 75, E 78.
• Appliance does not spin.
• Laundry creased.
• Time leaps in programme sequence.
• Error in programme sequence.
• Squeaking noises.
• Drive belt slipping.
• Drive belt dropped off.
5.2.1 Test BLDC motor
Replacement of BLDC motor is only permitted after testing. See below for a
description of the prerequisites for testing and replacement of the motor.
Prerequisite:
• The appliance is switched off for 5 min.
• The drive belt has been removed.
• The motor connector has been removed.
To allow the motor to rotate freely, remove the motor
connector!
Due to their design brushless motors do not rotate freely if the
motor connector is still in position and the appliance switched on.
2017-05-22 / DIS 113_58300000186503_ara_en_c
1. Turn the motor pinion with your hand.
Result:
The motor pinion does not turn easily or does not turn at all (blocked).
2. Check the motor pinion for damage.
Result:
The motor pinion is damaged. Indicator: There are scratch marks on the rear
panel in the area of the motor pinion.
3. Test the motor for noise by turning with your hand.
Result:
The motor makes a clattering or scraping sound. (Any jerking is OK)
4. Check the smell of the BLDC motor.
Result:
The BLDC motor gives off a scorched or burned smell.
5. Measure the motor winding on the motor connector at the measuring points
X 2.1-X 2.2, X 2.2-X 2.3, X 2.1-X 2.3.
Result:
The resistance is unequal to +/-10 % of the value shown in the circuit diagram.
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