Fuji Electric FRENIC-Ace series, User Manual

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Appendix A Trouble-free Use of Inverters (Notes on electrical noise)
Appendix-4
(2) Induction noise
When wires or signal lines of peripheral devices are brought close to the wires on the input and output sides of the
inverter through which noise current is flowing, noise will be induced into those wires and signal lines of the devices
by electromagnetic induction (Figure A-4) or electrostatic induction (Figure A-5). This is called “induction noise” (4).
Figure A-4 Electromagnetic Induced Noise
Figure A-5 Electrostatic Induced Noise
(3) Radiated noise
Noise generated in an inverter may be radiated through the air from wires (that act as antennas) at the input and
output sides of the inverter so as to affect peripheral devices. This noise is called “radiated noise” as shown below
as (5). Not only wires but motor frames or control system panels containing inverters may also act as antennas.
Figure A-6 Radiated Noise
Power source
(4) (4)
Electronic
equipment
Inverter
Signal line Sensor
Power source
(4)
Inverter
Signal line
Electronic
equipment
Sensor
Power source
(5)
Inverter
(5) (5) (5) (5) (5)
Electronic
equipment
Sensor
(4)