Electric Motor
MERGE 12-4
Chapter 12
Inspection and test of the motor element
Inspection of the armature
Disassemble the electric motor and carefully inspect the armature for any of the following characteristics:
•
The insulating material is charred, carbonized or ruptured;
•
The paint coating is abnormally hardened;
•
Tip-off;
•
The armature winding spreads outwards;
•
Armature core iron sheet is damaged;
•
The commutator is damaged or burnt;
•
The commutator is very dirty or has oil strain;
•
The commutator bar bulges up;
•
Armature bearing shaft is abraded.
Clean and wipe of the water on the dirty or stained commutator. The abnormal phenomena during
inspection can help spot the cause to the malfunction. The lightly coarse commutator can be polished by
400# or finer emery paper.
WARNING
• It is strictly prohibited to burnish the commutator with abrasive cloth. The grains on abrasive
cloth are conductive, and may result in the short circuit of the commutator bar. It is
prohibited to apply oil or lubricant to the commutator or brush.
NOTE: In case there is oil on the commuttor, the oil seal of the output shaft on the driving axle
may be damaged.
Armature earth test
WARNING
• It is strictly prohibited to immerse the armature into any solvent.
NOTE: Before testing the armature, wipe the armature with a piece of clean cloth. Wipe out
the carbon dust and metal particles between commutator bars.
1. Attach one probe of the multimeter set at 200
Ω
（
ohm
）
to the commutator and the other probe to the
armature core. The multimeter should indicate un-continuity (see Fig 12-4). In case of wrong
reading, the armature should be replaced.
Summary of Contents for 2010 E-Merge
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