4.4
Ground Connection
Install ground connections for the inverter and the motor by following the correct specifications to
ensure safe and accurate operation. Using the inverter and the motor without the specified
grounding connections may result in electric shock.
• Do not use the ground terminal as the signal (control) ground.
• Do not share the ground connection with other machines that consume a large amount of
power, such as a welding machine.
• Connect the ground cable to the nearest earth contact and keep the cable length as short as
possible.
Because the inverter is a high-frequency switching device, leakage current may occur during
operation. To avoid the danger of electrocution due to current leakage, the inverter must be
properly grounded. Ground connection must be made to the specified ground terminal on the
inverter. Do not connect ground cables to chassis screws.
• 200 V products require Class 3 grounding. Resistance to ground must be ≤ 100 Ω.
• 400 V products require Special Class 3 grounding. Resistance to ground must be ≤ 10 Ω.
The following table lists the minimum ground cable specifications that must be met to properly
ground the inverters.
Grounding wire size ( mm²)