Yale MPB040E Manual page 106

Brush and Commutator Inspection
Problem
Electrical burns on com-
mutator bars on opposite
sides of the commutator.
Copper wears rapidly at
the edge of the commuta-
tor bars.
8
Table 2. Commutator Problems (Continued)
Possible Cause
• Open armature
winding.
• Motor has been
stalled.
• Operation of the
motor in dirty and
abrasive condi-
tions.
• Wrong type of
brushes for this
motor and opera-
tion.
0620 YRM 0294
Illustration