Yaskawa Matrix Converter - Manual (Page 380)

10
-10
Motor Application Precautions
This section provides precautions for motor application.
‹ Using the MxC to Run an Existing Standard Motor
When a standard motor is operated with the MxC, power loss is slightly higher than when operated with a
commercial power supply. Observe the following precautions when using the MxC to operate an existing stan-
dard motor.
„ Low Speed Ranges
Cooling effects diminish in the low-speed range, resulting in higher motor temperatures. The motor torque
should be reduced in the low-speed range whenever using a non-Yaskawa motor. If 100% torque is required
continuously at low speeds, consider using a special inverter or vector motor.
„ Installation and Voltage Tolerance
Considerations must be made for the motor insulation voltage when the input voltage is high (440 V or higher)
or the motor wiring is too long. Contact your Yaskawa representative for more details.
„ Operating at High Speeds
When using the motor at a high speed (60 Hz or more), problems may arise in dynamic balance and bearing
durability. Contact your Yaskawa representative for more details.
„ Torque Characteristics
The motor may require more acceleration torque when the motor is operated with the MxC than when oper-
ated with a commercial power supply. Check the load torque characteristics of the machine to be used with the
motor to set a proper V/f pattern.
„ Resonance with the Natural Frequency of the Mechanical System
Take special care when a machine that has been operated at a constant speed is to be operated in Variable
Speed Mode. If there are any problems with resonance, then install oscillation-proof rubber on the motor base
or use the frequency jump function to skip any resonant frequencies in the application.
„ Imbalanced Rotor
Take special care when the motor is operated at a high speeds (60 Hz or more).
„ Noise
Noise varies with the carrier frequency. At high carrier frequencies, the noise is almost the same when the
motor is operated with a commercial power supply. Motor noise, however, becomes louder when the motor is
operated at a speed higher than the rated speed (60 Hz).