Omron EasySpeed 3G3JE User Manual page 37

Design
● Countermeasures against Radio Noise
Radio noise is generated from the Inverter as well as the input and output lines. Take the following
countermeasures to reduce radio noise.
• Keep the cable between the Inverter and the motor as short as possible.
• Install noise filters on both input and output sides, and also install the Inverter in a totally enclosed
steel box.
Three-phase
200 to 230 V AC
● Cable Length between Inverter and Motor
We recommend always keeping the wiring distance between the Inverter and motor to 50 m or less.
As the cable length between the Inverter and the motor increases, the floating capacity between the
Inverter outputs and the ground increases proportionally. The increase in floating capacity at the
Inverter output causes the high-frequency leakage current to increase, and this may adversely affect
peripheral devices and the current detector in the Inverter's output section.
If the cable must be longer than 50 meters, take the following countermeasures.
• Wire in metallic ducts.
• Use a separate cable for each phase.
• Reduce the carrier frequency selection (P14) (select 4 kHz).
● Single-phase Motors Cannot Be Used
The Inverter is not suited for the variable speed control of single-phase motors because they use
either capacitor starting or split-phase starting methods to determine the rotation direction at startup.
Do not use a single-phase motor.
Note If a capacitor start motor is used, the capacitor may be damaged by a sudden electric dis-
charge caused by Inverter output. If a split-phase start motor is used, the starting coil may burn
because the centrifugal switch does not operate.
MCCB
3G3IV-PLF310KA
3G3JE
Noise Filter
Inverter
Metal box
3G3IV-PLF310KA
Noise Filter
Chapter 2
M
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3
2-15