Omron SYSDRIVE 3G3JV User Manual page 45

Design
Induction Noise:
Radio Noise:
D Countermeasures against Induction Noise
As described previously, a Noise Filter can be used to prevent induction noise from being generated on
the output side. Alternatively, cables can be routed through a grounded metal pipe to prevent induction
noise. Keeping the metal pipe at least 30 cm away from the signal line considerably reduces induction
noise.
Power supply
D Countermeasures against Radio Interference
Radio noise is generated from the Inverter as well as the input and output lines. To reduce radio noise,
install Noise Filters on both input and output sides, and also install the Inverter in a totally enclosed steel
box.
The cable between the Inverter and the motor should be as short as possible.
Power supply
D Cable Length between Inverter and Motor
As the cable length between the Inverter and the motor is increased, the floating capacity between the
Inverter outputs and the ground is increased proportionally. The increase in floating capacity at the
Inverter outputs 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. To prevent this from occur-
ring, use a cable of no more than 100 meters between the Inverter and the motor. If the cable must be
longer than 100 meters, take measures to reduce the floating capacity by not wiring in metallic ducts, by
using separate cables for each phase, etc.
2-20
Electromagnetic induction generates noise on the signal line, causing the con-
troller to malfunction.
Electromagnetic waves from the Inverter and cables cause the broadcasting ra-
dio receiver to make noise.
3G3JV
SYSDRIVE
Signal line
Steel box
Noise
SYSDRIVE
Filter
Metal pipe
Controller
3G3JV
Noise
Filter
Chapter 2
30 cm min.
Metal pipe