Hartzell CD15K - 9.3.4 INSPECTION OF MOTOR ASSEMBLIES; 9.3.4.1 Inspect the fan for tip or blade damage. Fan nicks may be straightened as long as blades are not bent out of shape or balance is affected.; 9.3.4.2 Typically, unless the motor condition is in question, tear down and overhaul of the HET long-life motor even at overhaul (2000 hr.) is not necessary, unless one or more of the following is noticed the motor may continue in service.; 9.3.4.3 Motor disassembly and inspection may be accomplished by scribing a line on motor housing and end caps prior to bolt removal. This will ensure proper permanent magnet positioning when reassembled. The motor performance will be affected if cor...

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MM10001
Dated 1/1/08
Rev L dated 5/21/15
9.3.4 INSPECTION OF MOTOR ASSEMBLIES
9.3.4.1 Inspect the fan for tip or blade damage. Fan nicks may be straightened as long
as blades are not bent out of shape or balance is affected.
9.3.4.2 Typically, unless the motor condition is in question, tear down and overhaul of
the HET long-life motor even at overhaul (2000 hr.) is not necessary, unless one
or more of the following is noticed the motor may continue in service.
• End caps shift or are loose from housing.
• Excessive amounts of carbon are noticed.
• When commutator is slowly rotated, bearing squeak is present
• Commutator is loose or has lateral movement
• Cracked or damaged wiring.
9.3.4.3 Motor disassembly and inspection may be accomplished by scribing a line on
motor housing and end caps prior to bolt removal. This will ensure proper
permanent magnet positioning when reassembled. The motor performance will
be affected if correct alignment is not achieved when re-assembled. Inspect the
commutator on the armature. It should be smooth and medium brown to dark
brown in color. Use compressed air to remove all dust. If the commutator is
grooved in the brush track, gouged, scored, or shows signs of having burn spots,
replace the complete motor assembly. If the commutator is in good condition,
new brushes and bearings may be installed. Motor overhaul kits are available.
Always provide heater P/N and S/N when ordering motor overhaul kit. Inspect
motor brushes for wear. Replace if worn more than 50% (5/16”). If brushes are
in good condition, reinstall in the same position they were before removal to
ensure the curved ends fit the curvature of the armature.
NOTE:
• Motor style on far left cannot be overhauled
• Two styles on right can be overhauled with bearing and brush service kit P/N
29910
• An overhauled motor will not have as long of a service life as a new motor.
CAUTION – Do not touch armature with bare hands – oils will cause premature wear.
FIGURE 3
SINGLE
SHAFT
DOUBLE
SHAFT