Network Grounding - Toshiba nv Series Instruction Manual

Chapter 3 Installation and Wiring

Network grounding

3.5.4
In DeviceNet, the network is grounded at one point (Class D grounding for control devices)
Grounding at multiple points may cause ground loops. On the contrary, if the network is not grounded,
malfunctions can easily occur due to external noise.
The installation point of one-point ground is used as a power tap. Connect the ground terminal of the above-
mentioned power tap to the FG terminal of the power supply unit, and make a 3rd-class grounding (Figure
3-17). Also, ground as much as possible near the physical center of the network (place a power tap near the
center of the network and ground from the power tap)
If there are multiple power supplies on the network, ground only the power strip near the physical center of the
network if possible. Use a #8 AWG cable with a maximum length of 3 m for the ground cable.
Ground
terminal
Grounded power tap
42
6F8C1877
Power tap
V- V+
FG V- V+
Power supply
Figure 3-17 Network grounding method
Power tap
Ground
V- V+
terminal
FG V- V+
Power supply
Not grounded power tap