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M-AI-VT-001-EN Rev.C.1
Table 13
Nominal and Acceptable
Frequencies
Nominal Frequency
Acceptable Frequency Range
50Hz
50Hz ±5% (47Hz - 53Hz)
60Hz
60Hz ±5% (57Hz - 63Hz)
Environment and Application Boundaries
Refrigerant Type
The VTT series compressors are totally oil-free
and designed for use with refrigerant R134a.
Due to their use of magnetic bearings, Turbocor
compressor chiller systems are inherently oil-free.
Therefore, it is strongly recommended that all
system components in the refrigeration stream,
most notably expansion valves, solenoids, and
discharge check valves be approved by their
manufacturer for use in oil-free systems. In
addition, all chiller system components exposed
to refrigerant should be approved by their
manufacturer for use with that refrigerant
NOTE
The frequency ranges in the table above apply only when generator power is being used.
NOTE
Do not use recycled refrigerant as it may contain oil, which can affect system reliability. The refrigerant should
be pure and stored in virgin containers.
Table 14
Max Imbalance and Cycling
Max Imbalance and Cycling
Max. imbalance temporary between mains phases
3.0% of rated supply voltage
Switching on input supply (power ups)
Maximum one time/2 minutes
Mains voltage low:
During low mains voltage, the drive module
continues until the intermediate circuit voltage
drops below the minimum stop level, which
corresponds typically to 10% below the drive
module’s nominal voltage, then compressor will
trip with mains voltage fault.
Mains drop-out:
During mains drop-out, Kinetic back-up ensures
that the frequency converter keeps running
as long as there is energy in the system due to
the inertia from motor and load. This is done by
converting the mechanical energy to the energy
in the DC-link and thereby maintaining control of
the frequency converter and motor.
If the mains return while in Kinetic back-up, the
compressor will recover to normal operation and
begin increasing speed again provided that no
faults are present.
