Wiring Precautions - Fuji Electric FRENIC-HVAC User Manual

5.1.5

Wiring precautions

Follow the rules below when performing wiring for the inverter.
• 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 ground the inverter's grounding terminals
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 the inverter output terminals (U, V, and W).
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.
G.
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