Precautions for selecting peripheral devices
17
1
1.4
Precautions for selecting peripheral devices
1.4.1
Techniques and measures for electromagnetic
compatibility (EMC)
Some electromagnetic noises enter the converter to cause the converter malfunction, and others are radiated by the
converter to cause the peripheral devices to malfunction. (The former is called electromagnetic susceptibility (EMS) problem,
the latter is called electromagnetic interference (EMI) problem, and both is called electromagnetic compatibility (EMC)
problem.) Though the FR-XC series converter is designed to be immune to noises, it requires the following basic measures
and EMS measures as it handles low-level signals. Pay attention to the electromagnetic noises that could be generated by the
FR-XC series converter. If these noises cause peripheral devices to malfunction, EMI measures should be taken to suppress
noises. These techniques differ slightly depending on EMI paths.
Basic measures
• Do not run the power cables (I/O cables) and signal cables of the converter in parallel with each other and do not bundle
them.
• Use shielded twisted pair cables for the detector connecting and control signal cables and connect the sheathes of the
shielded cables to terminal SD.
• Ground (earth) the reactor, the converter, the inverter, etc. at one point.
EMS measures to reduce electromagnetic noises that enter the
converter and cause it to malfunction
When devices that generate many electromagnetic noises (which use magnetic contactors, electromagnetic brakes, many
relays, for example) are installed near the converter and the converter may malfunction due to electromagnetic noises, the
following countermeasures must be taken.
• Provide surge suppressors for devices that generate many electromagnetic noises to suppress electromagnetic noises.
• Install data line filters to signal cables.
• Ground (Earth) the shields of the detector connection and control signal cables with cable clamp metal.
EMI measures to reduce electromagnetic noises that are radiated by the
converter to cause the peripheral devices to malfunction
Converter-generated noises are largely classified into those radiated by the converter itself and by the cables (I/O)
connected to its main circuit, those electromagnetically and electrostatically induced to the signal cables of the peripheral
devices close to the power cable connected to the converter main circuit, and those transmitted through the power cables.
Noise propagated
through power supply
cable
…Path (c)
…Path (b)
…Path (a)
Noise directly radiated
from converter
…Path (d), (e)
Air propagated
noise
…Path (f)
Electrical path
propagated noise
…Path (h)
…Path (g)
Multifunction regeneration
converter generated
electromagnetic noise
Electromagnetic
induction noise
Electrostatic
induction noise
Noise radiated from
power supply cable
Noise radiated from
motor connection cable
Noise from earthing
(grounding) cable
due to leakage current
Instrument
Receiver
M
Sensor
power supply
Motor
Telephone
Sensor
(a)
(b)
(c)
(c)
(h)
(g)
(e)
(g)
(d)
(f)
(a)
Inverter
Multifunction
regeneration
converter
Dedicated reactor
or
box-type reactor
Summary of Contents for FR-XC-11K
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