Taylor-Dunn C0-425-36 Operation, Troubleshooting And Replacement Parts Manualooting And Replacement Parts Manual page 104

Motor Service
2. Measure the diameter of the commutator.
• If the commutator is less than the minimum
diameter specified in section
then the motor must be replaced.
3. Measure the commutator undercut depth in 5-places
around the commutator.
• If any one of the measurements is less than the
minimum undercut depth specified in
Limits
at the end of this section, then the
commutator must be undercut. Refer to
Commutator
section for information regarding
undercutting the commutator.
4. Inspect the commutator for groves.
• If the commutator is grooved then it must be
machined on a lathe. Do not machine the
commutator past the minimum diameter
Service Limits
specified in
Repair Commutator
regarding machining the commutator.
5. Inspect the commutator for burn marks.
• Burn marks and/or raised commutator segments
90 or 180 degrees apart is evidence of a shorted
armature. A tool called a growler is required to
reliably test for a shorted armature.
6. Inspect the commutator for raised segments. Raised
segments could be a result of a stalled motor or
shorted armature. A tool called a growler is required
to reliably test for a shorted armature.
• If the armature is not shorted then the raised
segments can be removed by machining the
commutator. Do not machine the commutator
past the minimum diameter specified in
Limits
section. Refer to
section for information regarding machining the
commutator.
Service Limits
,
Service
Repair
section. Refer to
section for information
Service
Repair Commutator
Motor Page 4
Hacksaw blade
Incorrect Correct
Insulation
Commutator
Typical burn mark on a shorted armature
Undercut
Armature
Min. OD