Electro-magnetic interference (EMI) and leakage currents
PRECAUTIONS FOR USE OF THE INVERTER
85
3
Data line filter
Data line filter is effective as an EMI countermeasure. Provide a data line filter for the detector cable, etc.
<Example> Data line filter : ZCAT3035-1330 (by TDK)
: ESD-SR-250 (by NEC TOKIN)
Impedance (ZCAT3035-1330)
The impedance values above are reference values,
and not guaranteed values.
EMI countermeasure example
Noise
propagation path
Countermeasure
(a)(b)(c)
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 86.)
• 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.
(d)(e)(f)
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.
(g)
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 86.)
• Install the line noise filter (FR-BLF, FR-BSF01) to the power cables (output cables) of the inverter.
(h)
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.
Impedance ()
10 to 100 MHz 100 to 500 MHz
80 150
34 1
TDK
39 1
Product name Lot number
30 1
Cable fixing band
mount
13 1
OUTLINE DIMENSION DRAWINGS (ZCAT3035-1330)
[Unit: mm]
Inverter
Sensor
Use a twisted pair shielded cable
Enclosure Decrease carrier frequency
Motor
M
FR-
BLF
Do not earth (ground) control cable.
Inverter
power
supply
Install filter (FR-BLF,
FR-BSF01) on
inverter output side.
Separate inverter and
power line by more than
30cm (at least 10cm)
from sensor circuit.
Control
power
supply
Do not earth (ground)
enclosure directly.
Power
supply for
sensor
Use 4-core cable for motor
power cable and use one cable
as earth (ground) cable.
Do not earth (ground) shield but
connect it to signal common cable.
EMC
filter