Mitsubishi Electric FR-A820-00046 Instruction Manual page 151

Precautions for use of the inverter
Fig. 3-4:
Noise
propagation
path
³ · »
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Tab. 3-4:
FR-A800
Instrument
Receiver
Noise paths
Countermeasure
When devices that handle low-level signals and are liable to malfunction due to electromagnetic
noises, e.g. instruments, receivers and sensors, are contained in the enclosure that contains the inverter
or when their signal cables are run near the inverter, the devices may malfunction due to by air-
propagated electromagnetic noises. The following countermeasures must be taken:
Install easily affected devices as far away as possible from the inverter.
Run easily affected signal cables as far away as possible from the inverter and its I/O cables.
Do not run the signal cables and power cables (inverter I/O cables) in parallel with each other and do
not bundle them.
Set the EMC filter ON/OFF connector of the inverter to the ON position. (Refer to page 3-9.)
Inserting a line noise filter into the output suppresses the radiated noise from the cables.
Use shielded cables as signal cables and power cables and run them in individual metal conduits to
produce further effects.
When the signal cables are run in parallel with or bundled with the power cables, magnetic and static
induction noises may be propagated to the signal cables to cause malfunction of the devices and the
following countermeasures must be taken:
Install easily affected devices as far away as possible from the inverter.
Run easily affected signal cables as far away as possible from the inverter and its I/O cables.
Do not run the signal cables and power cables (inverter I/O cables) in parallel with each other and do
not bundle them.
Use shielded cables as signal cables and power cables and run them in individual metal conduits to
produce further effects.
When the power supplies of the peripheral devices are connected to the power supply of the inverter
in the same line, inverter-generated noises may flow back through the power supply cables to cause
malfunction of the devices and the following countermeasures must be taken:
Set the EMC filter ON/OFF connector of the inverter to the ON position. (Refer to page 3-9.)
Install the line noise filter (FR-BLF, FR-BSF01) to the power cables (output cables) of the inverter.
When a closed loop circuit is formed by connecting the peripheral device wiring to the inverter, leakage
currents may flow through the earthing (grounding) cable of the inverter to cause the device to
malfunction. In that case, disconnecting the earthing (grounding) cable from the device may stop the
malfunction of the device.
Noise and Countermeasures
Electro-magnetic interference (EMI) and leakage currents
Sensor power
supply
Inverter
M
Sensor
Motor
3~
Telephone
I001049E
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