Raymond 8210 - Service

Model 8210/8250 Maintenance Manual Section 5. Troubleshooting
DC Electric Motors
Publication:1146945/001, Revised: 25 Sep 2018 5-9
Service
Some conditions, identified in Table 5-1, may
be resolved by cleaning the commutator with a
special polishing stone. Polishing the
commutator should only be attempted for the
specified conditions. Refer to “Polishing the
Commutator” on page 7-85 for instructions.
Some conditions can be resolved by recutting
the commutator on a lathe. This requires
special equipment and training and should only
be attempted at a qualified DC motor repair
facility.
Table 5-1. Commutator Surfaces
Condition Probable Cause Commutator Surface
Good Condition-Light Film Uniform coloring indicates satisfactory operation
of the machine and brushes. Acceptable film
color may vary from light to dark due to film
thickness.
Brushwear01.tif
Satisfactory
Condition-Light and Dark
Pattern
This condition can appear in alternating bars as
shown or every 3rd or 4th bar. This is caused by
imbalances in the windings or other motor
variances. It is not an indication of commutator
problems. The motor should have no issues
running, but the condition may indicate a need
for more frequent inspections.
Brushwea03.tif
Unsatisfactory
Condition-Streaky Film
With No Commutator Wear
Threading or streaked film on the commutator
surface. May be accompanied by rattling or loud
operation. This condition is frequently due to
incorrect brush grade. Environmental conditions,
such as freezer or low humidity, can be a
contributing factor. This condition may be
repaired with a polishing stone if caught soon
enough. Refer to “Polishing the Commutator” on
page 7-85.
Brushwear04.tif
Unsatisfactory
Condition-Uneven Film
Patchy colors of varying densities and shape.
This condition is generally due to unclean
operating conditions and does not indicate
damage to the commutator. Clean the
commutator with a polishing stone and
compressed air (see “Polishing the Commutator”
on page 7-85). Consider more frequent scheduled
maintenance intervals.
Brushwear05.tif
Unsatisfactory Condition-
Film With Dark Areas
Dark areas can be isolated or regular. This
condition indicates a commutator is
out-of-round. Continued use may result in
failure and damage to other systems. The motor
should be replaced or recut at a qualified repair
facility.
Brushwear06.tif
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