User manual

Chapter 2 Installation and Wiring

2.4.2 Main Circuit Wiring operation

Be sure that the motor is running forward when the running direction command of

inverter is forward. If the motor is running reverse, interchange any two output terminals

(U, V, W) can change the rotate direction of the motor, and you can change function code

P2.25 to change phase-sequence of the motor.

Never connect input power supply cables to output terminals, or else parts of the inverter

would be damaged. Do not connect output terminals to earth, be sure output cables not

touch to the shell or be shorted, or else the inverter would be damaged.

Be sure Earth terminal “PE” is connected to earth. The earthling resistance of 380V-class

should be below 10Ω. Be sure the earthling not be shared with an electric welding

machines or other high-current electrical equipments. Use ground wiring as mentioned

in “Appendix 3 Main Circuit Output Cable Selection” and keep the length as short as

possible.

When two or more inverters are used at the same time,

do not loop the wires. The right

and wrong earthling connection methods are shown as Figure 2-9.

Inverter

InverterRight

Inverter

InverterInverter

Wrong

Inverter

Fig 2-9 Earthling Connection Method

Attention: The neutral point of motor using Y connection can’t be connected to

earth.

Since the inverter output PWM wave, if a capacitance for improving power factor or a

lightning varistor is installed on the output side, which would case tripping or damage to

parts, be sure to remove it.

If a contactor or other on-off part is needed to be installed between the output and the

motor, be sure the on-off operation is done when the inverter has no output, otherwise the

inverter would be damaged.

Countermeasures to conduction interference: To inhibit conduction interference of the

output, besides installing noise filter and using shielded motor cables, leading all the

output cables to earthling metal tube is also a method. Make the distance between the

output cables and the control signal cables greater than 30 cm, the effect of conduction

interference will obviously decrease too.