Motor Cooling Exv Assembly; Removal And Installation; Figure 33 - Exv (Revision A Only); Figure 34 - Exv (Revisions B And Later) - Danfoss Turbocor VTT Series Service Manual

3.2.7 Motor Cooling EXV
Assembly
Figure 33 - EXV (Revision A
Only)
Figure 34 - EXV (Revisions B
and Later)
3.2.7.1 Removal and
Installation
Compressor Components
The Motor Cooling EXV controls the flow of refrigerant to cool the Compressor motor and bearing sections.
The motor cooling flow enters the Compressor in the Stator cooling groove through the expansion
valve, the flow 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 flange design. The O-ring is identical between the two (2) variants.
EXV Removal:
1. Isolate the Compressor power as described in the
section of this manual.
2. Isolate the Compressor and liquid line to the EXV and recover the refrigerant.
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.
"Electrical Isolation of the Compressor/VFD"
• • • CAUTION • • •
M-SV-VT-001-EN Rev. A
Torque to 70 Nm (52
ft.lb.) (4 places)
Torque to 30 Nm (22
ft.lb.) (2 places)
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