Omron SYSDRIVE 3G3MV User Manual page 343

Using the Inverter for a Motor Chapter 11
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 temperature. 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 Inverters.
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)
D High-speed Operation
When using the motor at high-speed (above the motor rated frequency), problems may
arise in dynamic balance and bearing 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.
11-2