43 of 165
M-SV-VT-001-EN Rev. A
Compressor Components
3.2.7 Motor Cooling EXV
Assembly
The Motor Cooling EXV controls the ow of refrigerant to cool the Compressor motor and bearing sections.
The motor cooling ow enters the Compressor in the Stator cooling groove through the expansion
valve, the ow then spirals around the motor Stator and into the rear of the Compressor. At this point
the temperature is measured and is used to ensure the refrigerant is superheated to a set level. The
cooling logic for the valve control is hence minimum superheat control. This control strategy ensures
that an optimal amount of refrigerant is inside the Stator with two-phase cooling (wetted surface). The
superheated gas is then used to cool the Rotor on the return to the exit via the airgap between the
Stator and Rotor.
There are two (2) variants of the EXV, both perform the same function but are not interchangeable due
to the mounting ange design. The O-ring is identical between the two (2) variants.
Figure 33 - EXV (Revision A
Only)
Figure 34 - EXV (Revisions B
and Later)
Torque to 70 Nm (52
ft.lb.) (4 places)
Torque to 30 Nm (22
ft.lb.) (2 places)
3.2.7.1 Removal and
Installation
EXV Removal:
1. Isolate the Compressor power as described in the “Electrical Isolation of the Compressor/VFD”
section of this manual.
2. Isolate the Compressor and liquid line to the EXV and recover the refrigerant.
• • • CAUTION • • •
Refrigerant may remain in the liquid line; ensure full recovery from high and low side of valve is
complete.
3. Remove the actuator coil from the EXV. The actuator coil is held on by a clip and it can be
removed by pulling straight away from the EXV.
To Next Page
Need help?
General
