Fuji Electric FRENIC-Ace series, User Manual

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Appendix A Trouble-free Use of Inverters (Notes on electrical noise)
Appendix-3
APPEN
DI
CES
[ 2 ] Types of noise
Noise generated in an inverter is propagated through the main circuit wiring to the power supply and the motor so
as to affect a wide range of applications from the power supply transformer to the motor. The various propagation
routes are shown in Figure A-2. According to those routes, noises are roughly classified into three
types--conducted noise, induction noise, and radiated noise.
Figure A-2 Noise Propagation Routes
(1) Conducted noise
The noise that has occurred in the inverter and propagates through a conductor to influence peripheral equipment
is called conducted noise. Some conducted noise will propagate through the main circuit (1). If the ground wires
are connected to a common ground, conducted noise will propagate through route (2). As shown in route (3), some
conducted noise will propagate through signal lines or shielded wires.
Figure A-3 Conducted Noise
Power transformer
ELCB
Inverter
Radio
Machine
Amplifier
(1)
(2)
(5)
(4)
(3)
Power source
(1)
(2)
Inverter
Signal line Sensor
(3)
Electronic
equipment