Assembly line procedure
Vacuum evacuation and
moisture removal
Refrigerant charging
Dielectric strength and
insulation resistance tests
Requirements:
• Never use the compressor to evacuate the
system.
• Connect a vacuum pump to both the LP and HP
sides.
• Evacuate the system to a pressure of 500 μm Hg
(0.67 mbar / 0.02 in.Hg) absolute.
Recommendations:
• Energized heaters improve moisture removal.
• Alternate vacuum phases and break vacuum.
with Nitrogen to improve moisture removal.
For more detailed information see “Vacuum
pump-down and dehydration procedure”
TI-026-0302.
Initial charge:
• For the initial charge, the compressor must not
run.
• Charge refrigerant as close as possible to the
nominal system charge.
• This initial charging operation must be done in
liquid phase between the condenser outlet and
the filter drier.
If needed, a complement of charge can be done:
• In liquid phase while compressor is running by
slowly throttling liquid in.
• Never bypass safety low pressure switch.
For more detailed information see
“Recommended refrigerant system charging
practice“ FRCC.EN.050.
The tests are performed on each compressor at
the factory between each phase and ground.
• Carry out a dielectric strength test by short-
circuiting terminals L1, L2 and L3. Energize by
max. 1920 V DC(hi-pot) for code G compressors
and 1460 V DC(hi-pot) for code J compressors
for one second between this short-circuit and
the chassis, and leakage current must be less
than 5 mA. When running dielectric strength
tests of the entire installation, frequency
converter and compressor electrical motor
compressor test can be conducted together.
When conducting a dielectric strength test,
make sure the system is not under vacuum: this
may cause electrical motor compressor failure.
Please note, it is not recommended that a
dielectric strength test be carried out too often
as it may damage the motor. Nevertheless, if
such a test is necessary, it must be performed at
a lower voltage.
• Insulation resistance is measured with a 500 V
DC megohm tester and must be higher than 1
megohm.
• The presence of refrigerant around the
motor windings will result in lower resistance
values to ground and higher leakage current
readings. Such readings do not indicate a faulty
compressor. To prevent this, the system can be
first operated briefly to distribute refrigerant.
Do not use a megohm meter nor apply
power to the compressor while it is under
vacuum as this may cause internal damage.
R
R
R
43
AB444226142054en-000101
Summary of Contents for VLZ065
Page 2: ......
Page 53: ...53 AB444226142054en 000101...
