Component Maintenance Manual
EFFECTIVITY: ALL
21-00-22
Page
11004
JULY 21, 2011
CAUTION
: CAREFULLY LAY BRUSH SHUNT LEADS IN A POSITION WHICH WILL PREVENT ANY
POSSIBLE SHORTING PROBLEMS. LEADS MUST EASILY FOLLOW BRUSH AND SPRING MOVEMENT
AS WEAR OCCURS. IMPROPER LEAD PLACEMENT MAY RESULT IN MOTOR DAMAGE.
12.4.7
If bearings rotate smoothly and are good, reinstall belt and brushes (refer to Assembly,
Section 9). Check belt alignment and tensioning (refer to Assembly, Section 9).
SUBTASK 21-00-22-20-002
12.5
Compressor Bearing Inspection:
12.5.1
Compressor bearing should be inspected every 1000-1500 operational hours to ensure that
premature seizure does not occur.
12.5.2
Gain access to the Compressor Condenser Module (refer to the aircraft maintenance
manual for removal of access panels and other hardware that might need to be removed).
12.5.3
Verify that power is removed from aircraft. If it is not practical to remove aircraft power,
technician must pull and collar applicable circuit breakers.
12.5.4
Rotate compressor pulley by hand to ensure freedom of movement and to ensure that the
pulley is not showing signs of loosening. Visually inspect bearing for sign of overheating or
loss of lubrication using an inspection mirror.
12.5.5
If bearings rotate smoothly and are in otherwise good condition, perform belt alignment and
tensioning (refer to Assembly, Section 9).
SUBTASK 21-00-22-82-004
12.6
Motor Brush Seating Procedure:
12.6.1
Cut 4” long by 1.5 “ wide strip of 400-500 grit paper and place, with rough side out, on motor
commutator. Secure one end of the paper to the commutator with masking tape in a
manner such that the taped end will lead in the direction of shaft rotation (CCW looking at
fan end). The other end will remain loose and overlap the taped end. Raise each brush
momentarily while rotating the shaft until the taped end passes under each brush. After the
grit paper is properly located tight against the commutator and encompasses all brush
surface area, carefully rotate the armature by hand in the normal direction of rotation until a
full seat is obtained on each new brush. Three to four rotations is generally adequate.
CAUTION
: EXCESSIVE SEATING IS NOT ADVISED OR BRUSH LIFE MAY BE REDUCED.
12.6.2
Remove grit paper and blow out all the carbon dust and other contamination from
commutator and brush area.
SUBTASK 21-00-22-20-003
12.7
Compressor Oil Level Check:
