2-10
2.3.4 Wiring
precautions
Follow the rules below when performing wiring for the inverter.
(1) Make sure that the power supply voltage is within the rated voltage range specified on the
nameplate.
(2) Be sure to connect the three-phase power wires to the main circuit power input terminals L1/R,
L2/S and L3/T, or connect the single-phase power wires to the main circuit power input terminals
L1/L and L2/N of the inverter. If the power wires are connected to other terminals, the inverter
will be damaged when the power is turned ON.
(3) Always connect the grounding terminal to prevent electric shock, fire or other disasters and to
reduce electric noise.
(4) Use crimp terminals covered with insulated sleeves for the main circuit terminal wiring to ensure
a reliable connection.
(5) Keep the power supply wiring (primary circuit) and motor wiring (secondary circuit) of the main
circuit, and control circuit wiring as far away as possible from each other.
• When wiring the inverter to the power supply, insert a recommended molded case circuit
breaker (MCCB) or earth leakage circuit breaker (ELCB) (with overcurrent protection) in
the path of each pair of power lines to inverters. Use the devices recommended ones
within the related current range.
• Use wires in the specified size.
• Tighten terminals with specified torque.
Otherwise, fire could occur.
• Do not connect a surge killer to the inverter's output circuit.
• Do not use one multicore cable in order to connect several inverters with motors.
Doing so could cause fire.
• Ground the inverter in compliance with the national or local electric code.
• Be sure to connect the grounding wire for the inverters grounding terminal G.
Otherwise, electric shock or fire could occur.
• Qualified electricians should carry out wiring.
• Be sure to perform wiring after turning the power off.
Otherwise, electric shock could occur.
• Be sure to perform wiring after installing the inverter.
Otherwise, 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.
• Do not connect the power supply wires to output terminals (U, V, and W).
Doing so could cause fire or an accident.
2.3.5 Wiring for main circuit terminals and grounding terminals
Table 2.8 shows the main circuit power terminals and grounding terminals.
Table 2.8 Symbols, Names and Functions of the Main Circuit Power Terminals
Symbol Name
Functions
L1/R, L2/S, L3/T
or L1/L, L2/N
Main circuit power
inputs
Connect the three-phase input power lines or single-phase
input power lines
U, V, W
Inverter outputs
Connect a three-phase motor.
P1, P(+)
DC reactor
connection
Connect an optional DC reactor (DCR) for improving power
factor.
P(+), DB
DC braking resistor
Connect an optional braking resistor.
P(+), N(-)
DC link bus
Connect a DC link bus of other inverter(s). An optional
regenerative converter is also connectable to these terminals.
G
Grounding for
inverter and motor
Grounding terminals for the inverter’s chassis (or case) and
motor. Earth one of the terminals and connect the grounding
terminal of the motor. Inverters provide a pair of grounding
terminals that function equivalently.