Mitsubishi Electric FATEC FR-A800 Manual page 114

7
REVIEW OF INSTALLATION ENVIRONMENT
(b) Reducing the noise radiated from the wire between the inverter and the motor
Although the radiated noise can be reduced by inserting the line noise filter FR-BLF or FR-
BSF01 to the inverter output side as described previously, it is usually reduced by using a
metallic pipe or shielded cable as shown in Fig. 7.23. For effective earthing (grounding) of
the motor, connect one cable of the 4-core cable on the inverter side and use a pipe whose
thickness is 2 mm or more.
Wiring inside the concrete pit or room surrounded by concrete has an effect similar to the
metallic pipe.
Power supply
Fig. 7.23 Pipe arrangement for the motor connection cable
(c) Reducing the noise radiated from the inverter
Usually, the noise radiated from an inverter is relatively small and does not matter.
However, when an inverter needs to be installed near a device susceptible to the noise
described above, store the inverter in a metal case as shown in Fig. 7.24, install a noise
filter at the power supply side, and connect a metallic pipe to the case at the output side.
Power
supply
Metal case
Inverter
Noise filter
Metal case
Inverter
Earth (ground)
Fig. 7.24 Reducing the noise radiated from the inverter
Metal conduit
or shield cable
IM
Earth (ground)
Metal conduit or shield cable
IM
7.2 Noise
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