Omron SYSDRIVE 3G3JV

11-2
H Using Inverter for Existing Standard Motor
When a standard motor is operated with the Inverter, a power loss is lightly higher than when operated
with a commercial power supply.
In addition, cooling effects also decline the low-speed range, resulting in an increase in the motor tem-
perature. Therefore, motor torque should be reduced in the low speed range.
The following figure shows allowable load characteristics of a standard motor.
If 100% torque is continuously required in the low-speed range, use a special motor for use with Invert-
ers.
Allowable Load Characteristics of Standard Motor
25% ED (or 15 min)
40% ED (or 20 min)
60% ED (or 40 min)
Torque (%)
Continuous
Frequency (Hz)
100
80
70
60
50
06020103
D High-speed Operation
When using the motor at high-speed (60 Hz or more), problems may arise in dynamic balance and bear-
ing durability.
D Torque Characteristics
The motor may require more acceleration torque when the motor is operated with the Inverter than
when operated 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.
D Vibration
The 3G3JV Series employs high carrier PWM control to reduce motor vibration. When the motor is op-
erated 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.
• Imbalance rotor
Take special care when the motor is operated at a high speed (60 Hz or more).
Using the Inverter for a Motor Chapter 11