Refrigerant Type - Danfoss VTT Series Applications And Installation Manual

Table 13
Nominal and Acceptable
Frequencies
Table 14
Max Imbalance and Cycling

Refrigerant Type

Environment and Application Boundaries
Nominal Frequency
50Hz
60Hz
The frequency ranges in the table above apply only when generator power is being used.
Max. imbalance temporary between mains phases
Switching on input supply (power ups)
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
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
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.
Acceptable Frequency Range
50Hz ±5% (47Hz - 53Hz)
60Hz ±5% (57Hz - 63Hz)
NOTE
Max Imbalance and Cycling
3.0% of rated supply voltage
Maximum one time/2 minutes
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.
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
M-AI-VT-001-EN Rev.C.1
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