Inovance MD290 Series, Advanced User'S Manual

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Appendix
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12
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Cabling Requirements
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Motor cable and PE shielded conducting wire (twisted shielded) should be as short as
possible to reduce electromagnetic radiation and external stray current and capacitive
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is required.
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It is recommended that all control cables be shielded.
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It is recommended that motor cables, power input cables and control cables be laid
in different ducts. To avoid electromagnetic interference caused by rapid change of
output voltage of AC drive, motor cables and other cables must not be laid side by
side for a long distance.
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If control cable must run across power cable, make sure they are arranged at an
angle of close to 90°. Other cables must not run across AC drive.
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Power input and output cables of AC drive and weak-current signal cables (such as
control cable) should be laid vertically (if possible) rather than in parallel.
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Cable ducts must be in good connection and well grounded. Aluminium ducts can be
used to improve electric potential.
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Filter, AC drive and motor should be connected to system (machinery or appliance)
properly, with spraying protection at installation part and conductive metal in full
contact.
A.1.8 Solutions to Current Leakage
AC drive outputs high-speed pulse voltage, producing high-frequency leakage current during
running of the drive. Each AC drive produces more than 100 mA leakage current. Therefore, it
is necessary to select a residual current circuit-breaker with rated operating current of 100 mA
above.
AC drive generates DC leakage current in protective conductor. In this case, a time-delay B-type
breaker must be used. If multiple AC drives are required, each AC drive must be installed with a
circuit-breaker.
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AC drive capacity
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Carrier frequency
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Type and length of motor cable
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When leakage current causes the circuit-breaker to act, you should:
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Increase sensitivity current of circuit-breaker.
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Replace circuit-breaker with a new one with high-frequency suppression function.
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Reduce carrier frequency.
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Shorten length of the output cable.
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Install a current leakage suppression device.
Recommended residual current circuit-breaker manufacturers are Chint Electric and Schneider.