Notices regarding the use of inverter drives
- Maximum motor speed
The maximum motor speed depends on the motor specifications.
Please confirm the specifications of the manufacturer of your motor.
The specifications of TOSHIBA motors are as follows:
- Low speed operation
Generally motors need to reduce their output torque when operating under 30Hz.
The motors are cooled by fans mounted on their shafts, so when the motor speed decreases, the cooling efficiency also decreases.
Special motors for inverter drives don't need to reduce their output torque between 6 to 60Hz.
- Acceleration and deceleration time
In case of high speed operation, a larger acceleration/deceleration time should be selected.
When you set a short acceleration/deceleration time. you sometimes have the following problems:
While accelerating: Trip caused by overcurrent
While decelerating: Trip caused by overvoltage
We recommend to use the braking resistor for short time deceleration.
- Electromagnetic noise
The inverter is generating "electromagnetic noise".
If there are some high accuracy sensors or other sensitive equipment near the inverter drive, the inverter's noise may cause some trouble or a malfunction.
Electromagnetic noise can be avoided by installing an external noise filter or using a different wiring method.
The inverter is generating "harmonics".
These harmonics sometimes cause a malfunction in other control equipment that is connected to the same power source.
Harmonics can be avoided by installing an external "reactor".
To decrease "harmonics", we recommend to install DC reactors in all our inverter models.
(NOTE: 100V input models require AC reactors.)