Mitsubishi Electric FR-A701 Instrucion Manual page 45

EMC and leakage currents
Propagation Path
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 be malfunctioned by air-propagated
electromagnetic noises. The following measures must be taken:
(1) Install easily affected devices as far away as possible from the inverter.
(2) Run easily affected signal cables as far away as possible from the inverter and its I/O cables.
1) 2) 3)
(3) Do not run the signal cables and power cables (inverter I/O cables) in parallel with each other and do
(4) Insert common mode filters into I/O and capacitors between the input lines to suppress cable-
(5) Use shield cables as signal cables and power cables and run them in individual metal conduits to
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 malfunction the devices and the following
measures must be taken:
(1) Install easily affected devices as far away as possible from the inverter.
4) 5) 6) (2) Run easily affected signal cables as far away as possible from the I/O cables of the inverter.
(3) Do not run the signal cables and power cables (inverter I/O cables) in parallel with each other and do
(4) Use shield cables as signal cables and power cables and run them in individual metal conduits to
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 malfunction
7)
the devices. In such a case, installing the common mode filter (FR-BLF) to the power cables (output
cable) of the inverter will prevent malfunction.
When a closed loop circuit is formed by connecting the peripheral device wiring to the inverter, leakage
8) currents may flow through the earth (ground) cable of the inverter to malfunction the device. In such a
case, disconnection of the earth (ground) cable of the device may cause the device to operate properly.
Data line filter
As immunity measures it may effective, provide a data line filter for the detector cable etc.
EMC measures
Install common mode filter (FR-BLF)
on inverter input side.
Install capacitor type FR-BIF filter
on inverter input side.
Separate inverter and power
line by more than 30cm (at
least 10cm) from sensor circuit.
38
not bundle them.
radiated noises.
produce further effects.
not bundle them.
produce further effects.
Enclosure
Inverter
power
supply
Control
power
supply
Do not earth (ground)
enclosure directly.
Do not earth (ground) control cable.
Measures
Decrease
carrier frequency
FR- FR-
Inverter
BLF BLF
FR-
BIF
Use a twisted pair shielded cable
Power
supply
for sensor
Do not earth (ground) shield but
connect it to signal common cable.
Install common mode filter (FR-BLF)
on inverter output side.
IM Motor
Use 4-core cable for motor
power cable and use one
cable as earth (ground) cable.
Sensor