2 Engineering
2.9 Single-phase AC motors
DC1-S…20…, DC1-S…OE1 Variable Frequency Drives
05/21 MN040058EN
www.eaton.com
43
The capacitor is sized optimally for a single speed and torque load case and
depends on the motor’s design. If the capacitor is optimally sized, it will be
possible to achieve approximately 65 % of the mechanical output that would
be possible with a comparable three-phase asynchronous motor. For
operation on a 230 V/50 Hz mains, a capacitor capacitance of approximately
30 to 50
μ
F per kW of motor output is recommended.
PSC motors are used when outputs of up to around 2.2 kW (3 HP) are
required, as is the case with small machine tools and construction
equipment, swimming pool pumps, room ventilation fans, compressors in
refrigerators, washing machines, mills, and small and mobile belt conveyors.
2.9.5 Capacitor-start/capacitor-run motors
Figure 17: Capacitor-start/capacitor-run motor
When capacitors with large capacitances (start capacitor) are switched at the
output of a variable frequency drive, high current and voltage peaks may be
produced. These peaks, in turn, can cause undesired DC1-S… variable
frequency drive shutdowns and inverter damage.
NOTICE
Running motors with a start capacitor and run capacitor on a
DC1-S… variable frequency drive is not permissible!
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Summary of Contents for PowerXL
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