ii
Wiring
• If no zero-phase current (earth leakage current) detective device such as a ground-fault relay is installed in the upstream
power supply line in order to avoid the entire power supply system's shutdown undesirable to factory operation, install
a residual-current-operated protective device (RCD)/earth leakage circuit breaker (ELCB) individually to inverters to
break the individual inverter power supply lines only.
Otherwise, a fire could occur.
• When wiring the inverter to the power source, insert a recommended molded case circuit breaker (MCCB) or
residual-current-operated protective device (RCD)/earth leakage circuit breaker (ELCB) (with overcurrent protection)
in the path of each pair of power lines to inverters. Use the recommended devices within the recommended current
capacity.
• Use wires in the specified size.
• Tighten terminals with specified torque.
Otherwise, a fire could occur.
• When there is more than one combination of an inverter and motor, do not use a multicore cable for the purpose of
handling their wirings together.
• Do not connect a surge killer to the inverter's output (secondary) circuit.
Doing so could cause a fire.
• Be sure to connect an optional DC reactor (DCR) when the capacity of the power supply transformer exceeds 500 kVA
and is 10 times or more the inverter rated capacity.
Otherwise, a fire could occur.
• Ground the inverter in compliance with the national or local electric code.
• Be sure to ground the inverter's grounding terminals
G.
Otherwise, an electric shock or a fire could occur.
• Qualified electricians should carry out wiring.
• Be sure to perform wiring after turning the power OFF.
Otherwise, an electric shock could occur.
• Be sure to perform wiring after installing the inverter unit.
Otherwise, an electric shock or injuries could occur.
• Ensure that the number of input phases and the rated voltage of the product match the number of phases and the voltage
of the AC power supply to which the product is to be connected.
Otherwise, a fire or an accident could occur.
• Do not connect the power supply wires to output terminals (U, V, and W).
• When connecting a DC braking resistor (DBR), never connect it to terminals other than terminals P(+) and DB.
Doing so could cause fire or an accident.
• In general, sheaths of the control signal wires are not specifically designed to withstand a high voltage (i.e., reinforced
insulation is not applied). Therefore, if a control signal wire comes into direct contact with a live conductor of the main
circuit, the insulation of the sheath might break down, which would expose the signal wire to a high voltage of the main
circuit. Make sure that the control signal wires will not come into contact with live conductors of the main circuit.
Doing so could cause an accident or an electric shock.
• Before changing the switches or touching the control circuit terminal symbol plate, turn OFF the power and wait at
least five minutes for inverters with a capacity of 22 kW or below, or at least ten minutes for inverters with a
capacity of 30 kW or above. Make sure that the LED monitor and charging lamp are turned OFF. Further, make sure,
using a multimeter or a similar instrument, that the DC link bus voltage between the terminals P(+) and N(-) has
dropped to the safe level (+25 VDC or below).
Otherwise, an electric shock could occur.
• The inverter, motor and wiring generate electric noise. Be careful about malfunction of the nearby sensors and devices.
To prevent them from malfunctioning, implement noise control measures.
Otherwise an accident could occur.
• The leakage current of the EMC filter built-in type of inverters is comparatively large. Be sure to perform protective
grounding.
Otherwise, an electric shock could occur.
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