Types Of Noise And Propagation Path - Mitsubishi Electric FATEC FR-A800 Manual

7
REVIEW OF INSTALLATION ENVIRONMENT
7.2.2

Types of noise and propagation path

The inverter-generated noise is largely classified into those radiated by the cables connected to the
inverter and inverter main circuits (I/O), those electromagnetically and electrostatically induced to the
signal cables of the peripheral devices close to the main circuit power supply, and those transmitted
through the power supply cables.
Fig. 7.12 shows the types of noise, and Fig. 7.13 shows the path of noise.
Noise generated
from the inverter
Instrument
Each noise level tends to be decreased as the frequency band rises. In general, it does not matter in
the frequency band of 30 MHz or more.
Therefore, it does not affect much the televisions or FM radios that use frequency 30 MHz or more
with some exceptions. However, it affects low frequency band (0.5 to 10 MHz) radios such as AM
radios.
Accordingly, it is rational to consider the countermeasures with regard to the frequency band of the
noise.
Air propagated noise 空中伝播ノイズ
Electromagnetic
電磁誘導ノイズ
induction noise
Electrostatic
induction noise
Electrical path
propagated noise
Fig. 7.12 Types of noise
5)
7)
2)
7)
1)
Inverter
3)
Receiver
4)
Motor
IM
Fig. 7.13 Path of noise
Noise directly radiated
from the inverter
Noise radiated from
the power supply cable
Noise radiated from the
motor connection cable
4), 5)
Path
· · ·
Path 6)
· · ·
Noise propagated
through the power
supply cable
Noise from the
earthing (grounding)
cable due to leakage
current
Telephone
7)
Sensor
2)
power supply
6)
8)
Sensor
3)
7.2 Noise
· · · Path 1)
· · · Path 2)
Path 3)
· · ·
· · · Path 7)
Path 8)
· · ·
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