Chapter 15: Appendix
[2] Wiring power lines and grounding equipment
This section describes how to wire power lines and ground lines in a distribution panel, or controller panel for the
When wiring power lines and making grounds, observe the precautions below.
1.Isolate the control power circuit from the controller power circuit using an isolation transformer with a static electricity protective function.
2.Ground the frames of the distribution panel and the control panel using class D grounding.
3.Provide an exclusive class D or better ground to the controller FG (frame ground) terminal. Do not connect this terminal to the controller frame.
4.The wiring for the power line to the controller should be as short as possible, using twisted power cables.
5.Connect the LG (line ground) terminal on the controller to the shield terminal on the isolation trans- former, and then to the frame ground on the panel.
Control | Distribution | Operation | Control panel |
power | panel | preparation |
|
|
| Relay circuit |
|
PLC, etc.
| Panel | Panel ground | Controller ground |
Class | ground | (5.5 mm2 or larger) | (5.5 mm2 or larger) |
| Class | Class | |
D ground | D ground | D ground | |
An example of how to ground the
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