2-15
The wiring procedure for the FRN0006C2S-2A is given below as an example. For other inverter
types, perform wiring in accordance with their individual terminal arrangement. (Refer to page 2-5.)
Grounding terminal ( G)
Be sure to ground either of the two grounding terminals for safety and noise reduction. It is stipulated
by the Electric Facility Technical Standard that all metal frames of electrical equipment must be
grounded to avoid electric shock, fire and other disasters.
Grounding terminals should be grounded as follows:
1) Ground the inverter in compliance with the national or local electric code.
2) Connect a thick grounding wire with a large surface area. Keep the wiring length as short as
possible.
Inverter output terminals, U, V, W and grounding terminal ( G)
1) Connect the three wires of the three-phase motor to terminals U, V, and W, aligning phases each
other.
2) Connect the grounding wire of terminals U, V, and W to the grounding terminal ( G).
3) If the cable from the inverter to the motor is very long, a high-frequency current may be generated
by stray capacitance between the cables and result in an overcurrent trip of the inverter, an in-
crease in leakage current, or a reduction in current indication precision.
When a motor is driven by a PWM-type inverter, the motor terminals may be subject to surge voltage
generated by inverter element switching. If the motor cable (with 460 V series motors, in particular) is
particularly long, surge voltage will deteriorate motor insulation. To prevent this, use the following
guidelines:
Inverters of 7.5 HP(5.5kW) or above
Motor Insulation Level
1000 V
1300 V
1600 V
400 VAC class Input Voltage 20 m (66 ft)
100 m (328 ft)
400 m (1312 ft)*
200 VAC class Input Voltage 400 m (1312 ft)*
400 m (1312 ft)*
400 m (1312 ft)*
Inverters of 5 HP(3.7kW)/4.0kW or below
Motor Insulation Level
1000 V
1300 V
1600 V
400 VAC class Input Voltage 20 m (66 ft)
50 m (164 ft)
50 m (164 ft)*
200 VAC class Input Voltage 100 m (328 ft)*
100 m (328 ft)*
100 m (328 ft)*
* For this case the cable length is determined by secondary effects and not voltage spiking.
If it is not possible to fulfill the guidelines above, follow the instruction below.
The wiring length between the inverter and motor should not exceed 50 m (164 ft). If it
exceeds 50 m (164 ft), it is recommended that an output circuit filter (option) be inserted.
- Do not use one multicore cable to connect several inverters with motors.
