YASKAWA UAK series User Manual page 149

7 Wiring
7.2.1 Main Circuit
(10) Grounding
Use the following information to ensure that the ground is sufficient.
• Make sure to ground the ground terminal (
200 V class: Ground to 100 Ω or less
400 V class: Ground to 10 Ω or less
• Never ground the Σ-V-SD driver in common with welding machines, motors, or other large current electri-
cal equipment. Wiring for grounding cable must be separated from the large-current electrical equipment.
• Always use a ground wire that complies with technical standards on electrical equipment. Minimize the
length of the ground wire. Leakage current flows through the Σ-V-SD driver. Therefore, if the distance
between the ground terminal and the ground terminal is too long, the potential on the ground terminal of the
Σ-V-SD driver will become unstable.
• Always ground Σ-V-SD driver and motors using a ground terminal even when equipment is grounded
through sill channel or steel plate.
• Ground each Σ-V-SD driver directly to the ground as shown in the following figure (a). Do not make a loop
as shown in (b).
• Ground the Σ-V-SD driver and motor as shown in the following figure (a). Do not ground both the Σ-V-SD
driver and motor as shown in (b).
7-24
).
Correct Incorrect
(a) Acceptable
(b) Not Acceptable
Grounding
Correct
(a) Acceptable
(b) Not Acceptable
Grounding of Motor and Σ-V-SD Driver
Incorrect