LS ELECTRIC SV-iS7 Series, User Manual

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Connecting the Cables
57
4.3 Precautions for Wiring the Inverter
• Do not connect power to the inverter until installation has been fully completed and the inverter
is ready to be operated. Doing so may result in electric shock.
• Wiring and inspection of wiring must be performed by an authorized engineer.
• Install the inverter before connecting the cables.
• Ensure that no metal debris, such as wire clippings, remain inside the inverter. Metal debris in
the inverter can cause inverter failure.
• Power supply cables must be connected to the R, S, and T terminals. Connecting power cables
to other terminals will damage the inverter.
• Use insulated ring lugs when connecting cables to R/S/T and U/V/W terminals.
• The inverter ’ s power terminal connections can cause harmonics that may interfere with other
communication devices located near the inverter. To reduce interference, the installation of
noise filters or line filters may be required.
• To avoid circuit interruption or damaging connected equipment, do not install phase-advanced
condensers, surge protection, or electronic noise filters on the output side of the inverter.
• To avoid circuit interruption or damaging connected equipment, do not install magnetic
contactors on the output side of the inverter.
• Make sure that the total cable length does not exceed 495 ft (150 m). For inverters < = 3.7 kW
capacity, ensure that the total cable length does not exceed 165 ft (50 m). Long cable runs can
cause reduced motor torque in low frequency applications due to voltage drop. Long cable runs
also increase a circuit ’ s susceptibility to stray capacitance and may trigger over-current
protection devices or result in the malfunction of equipment connected to the inverter.
• Route the signal cables away from the power cables. Otherwise, signal errors may occur due to
electric interference.
• Tighten terminal screws to their specified torques. Loose terminal block screws may allow the
cables to disconnect and cause a short circuit or inverter failure. Refer to 4.7 Specifications of the
Power Terminal Block and Exterior Fuse on page 6666 for torque specifications.
• Do not place heavy objects on top of electric cables. Heavy objects may damage the cable and
result in electric shock.
• Use cables with the largest cross-sectional area, appropriate for power terminal wiring, to
ensure that voltage drops do not exceed 2%.
• Use copper cables rated at 600 V, 75
℃
for power terminal wiring.
• Use copper cables rated at 300 V, 75
℃
for control terminal wiring.
• If you need to rewire the terminals due to wiring-related faults, ensure that the inverter keypad
display is turned off and the charge lamp under the terminal cover is off before working on
wiring connections. The inverter may hold a high-voltage electric charge long after the power
supply has been turned off.