Omron SYSDRIVE 3G3RV, User Manual

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Motor Application Precautions
10-
5
10
Motor Application Precautions
This
section provides precautions for motor application.
K K K K
Using the Inverter for an Existing Standard Motor
When
a standard motor is operated with the Inverter, power loss is slightly higher than when operated with a
commercial
power supply. Observe the following precautions when using an Inverter for an existing standard
motor.
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Low-speed Range
Cooling
effects diminish in the low-speed range, resulting in an increase in the motor temperature. Therefore,
the
motor torque should be reduced in the low-speed range whenever using a motor not made by OMRON. If
100%
torque is required continuously at low speed, consider using a special inverter or vector motor.
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Installation Withstand Voltage
If
the input voltage is high (440 V or higher) or the wiring distance is long, the motor insulation voltage must
be
considered. Contact your dealer for details.
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High-speed Operation
When
using the motor at a high speed (60 Hz or more), problems may arise in dynamic balance and bearing
durability.
Contact your dealer for details.
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Torque Characteristics
The
motor may require more acceleration torque when the motor is operated with the Inverter 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.
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Vibration
The
Inverter uses a high carrier PWM to reduce motor vibration. (A parameter can be set to select low carrier,
PWM
modulation control as well.) When the motor is operated with the Inverter, motor vibration is almost the
same
as when operated with a commercial power supply.
Motor
vibration may, however, become greater in the following cases.
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 resonance occurs, install vibration-proof rubber on the motor base or use the frequency jump function
to
skip any frequency resonating the machine.
Unbalanced Rotor
Take
special care when the motor is operated at a higher speed (60 Hz or more).
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Noise
Noise
varies with the carrier frequency. At high carrier frequencies, the noise is almost the same as 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).