Lennox T?CLASS TPA024S4 Unit Information page 7

SUCTION
SUCTION
POCKET
SUCTION
DETAIL C
REVERSING VALVE L1 AND SOLENOID
A refrigerant reversing valve with electromechanical
solenoid is used to reverse refrigerant flow during unit
operation. The reversing
maintenance. The only replaceable part is the solenoid.
If the reversing valve itself has failed, it must be
replaced.
If replacement is necessary, access reversing valve by
removing the outdoor fan motor. Refer to figure 1.
BI−FLOW DRIER
A filter drier designed for all TPA4*S4 model units is
located in the liquid line. The field installed drier is designed
to remove moisture, which can lead to compressor failure.
Any time unit is exposed to open air due to service,
drier must be replaced. All replacement driers must be
approved for HFC−410A refrigerant.
COMPRESSOR
All TPA*S4 units utilize a scroll compressor. The scroll
compressor design is simple, efficient and requires few
moving parts. A cutaway diagram of the scroll compressor is
illustrated in Figure 4. The scrolls are located in the top of the
compressor can and the motor is located just below. The oil
level is immediately below the motor.
The scroll is a simple compression concept centered around
the unique spiral shape of the scroll and its inherent
properties. Two identical scrolls are mated together forming
concentric spiral shapes as illustrated in Figure 5. One scroll
remains stationary, while the other is allowed to orbit. Note
that the orbiting scroll does not rotate or turn but merely orbits
the stationary scroll.
NOTE − During operation, the head of a scroll compressor
may be hot since it is in constant contact with discharge gas.
DETAIL A
ORBITING SCROLL
STATIONARY SCROLL
FLANKS SEALED
BY CENTRIFUGAL
MOVEMENT OF ORBIT
HIGH PRESSURE GAS
Figure 3. Scroll Compressors
valve requires no
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SUCTION
SUCTION
FORCE
DETAIL D
DISCHARGE
SUCTION
Figure 4. Scroll Compressor
DISCHARGE
DISCHARGE
PRESSURE
TIPS SEALED BY
DISCHARGE PRESSURE
Figure 5. Scroll Cross−Section
INTERMEDIATE PRESSURE
GAS
CRESCENT
SHAPED
GAS POCKET
DETAIL B
DISCHARGE
POCKET
STATIONARY SCROLL
SUCTION
ORBITING SCROLL