Component Maintenance Manual
EFFECTIVITY: ALL
21-00-22
Page
11003
JULY 21, 2011
12.2.5
Allow system to stabilize, recheck the evaporator outlet temperatures and repeat adjustment
procedure if required. Evaporator outlet temperatures should be within 1-3° of each other.
NOTE
: Proper evaporator balancing should not result in a change of the compressor suction pressure. Verify
system pressures are typical values as shown in table 5.
12.2.6
If the evaporator’s outlet temperature is equal and the suction pressure is typical, then
servicing is complete. Shut system off and replace all shrouds, enclosures, ducting, as
required and remove charging/measurement equipment. If not, repeat adjustment
procedure until temperatures are equal and suction pressure is typical.
SUBTASK 21-00-22-82-003
12.3
Motor Insulation Resistance Check:
12.3.1
After the inspection of the commutator, a quick check of the motor insulation resistance
should be performed. This check may be done with or without the brushes installed, but the
power leads must be removed from the motor during this procedure.
12.3.2
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)
12.3.3
Verify that power is removed from aircraft. If it is not practical to remove aircraft power,
technician must pull and collar applicable circuit breakers.
12.3.4
With OHM meter positive lead connected to the motor positive terminal and the other lead
connected to motor case (grnd), measure and record resistance. Resistance value must be
equal to or greater than 10,000 OHM’s. If less, the motor should be replaced.
SUBTASK 21-00-22-20-001
12.4
Motor Bearing Inspection:
12.4.1
Motor bearing should be inspected every 800-1000 operational hours to ensure that
premature seizure does not occur.
12.4.2
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)
12.4.3
Verify that power is removed from aircraft. If it is not practical to remove aircraft power,
technician must pull and collar applicable circuit breakers.
12.4.4
Remove brush cover (on some systems, removal of power leads is required prior to brush
cover removal, tag positive terminal).
12.4.5
Remove brushes from guides and remove belt from motor pulley (refer to Disassembly,
Section 5).
12.4.6
Rotate motor shaft by hand to ensure freedom of movement. Visually inspect bearing for
sign of overheating or loss of lubrication using an inspection mirror.