Mitsubishi Electric FATEC FR-A800 Manual page 109

7
REVIEW OF INSTALLATION ENVIRONMENT
(1) Air propagated noise (Path 1) to 3))
The noise generated by an inverter is radiated and transmitted into the air following the three
paths as shown in Fig. 7.14.
2) Radiation from the input cable
Power
supply
2) Radiation from the input cable
(2) Electromagnetic induction noise (Path 4), 5))
The noise is transmitted by the interlinkage of
the power supply cables and signal cables for
the peripheral devices in the magnetic field
that is generated by the I/O side current of the
inverter. (Refer to Fig. 7.15.)
When both cables are close and parallel, or
when the loop of each cable is large, the
inducted noise increases.
(3) Electrostatic induction noise (Path 6)
The noise is transmitted when the electric
field that is generated by the I/O cables of
the inverter is coupled with the signal
cables through the static capacitance.
(Refer to Fig. 7.16.)
(4) Electrical path propagated noise (Path 7)
The high frequency noise generated in the
inverter is transmitted to the peripheral
devices through the cables at the power
supply side. (Refer to Fig. 7.17.)
7.2 Noise
104
1) Radiation from the inverter
Inverter
Earth (ground)
Fig. 7.14 Air propagated noise
Connected
device
3) Radiation from the motor
connection cable
3) Radiation from the motor
connection cable
IM
(Motor frame earth (ground))
Inverter
Connected
device
Fig. 7.15 Electromagnetic induction noise
Inverter
C
Fig. 7.16 Electrostatic induction noise
Inverter
Connected
device
Fig. 7.17 Electrical path propagated noise
Motor
IM
Signal source
(such as a sensor)
Motor
IM
C (static capacitance)
Signal source
(such as a sensor)
Motor
IM
Signal source