Grounding - Omron NX701-1700 User Manual

4 Installation and Wiring
• Either install the Controller a minimum of 200 mm away from high-voltage lines or power lines, or
place the high-voltage lines or power lines in metal tubing and completely ground the metal tubing
to 100 Ω or less.
High-voltage power panel
Power lines
200 mm
Controller
Example: Separating Controller from Power Lines
 Other Precautions
• Basic I/O Units have both plus and minus commons, so pay attention to the polarity when wiring.
4-5-6

Grounding

This section describes the earthing methods and precautions.
Considerations for Earthing Methods
Local potential fluctuations due to lightning or noise occurred by power devices will cause potential fluc-
tuations between ground terminals of devices. This potential fluctuation may result in device malfunc-
tion or damage. To prevent this, it is necessary to suppress the occurrence of a difference in electrical
potential between ground terminals of devices. You need to consider the earthing methods to achieve
this objective.
The recommended earthing methods for each usage condition are given in the following table.
Specification of communications cables
for EtherCAT and EtherNet/IP
The cable shield connected to the connector
hood at both ends of the communications
*1
cable
The cable shield connected to the connector
hood at only one end of the communications
*2
cable
Neither EtherCAT nor EtherNet/IP used
*1. Use this cable when using EtherCAT or when using EtherNet/IP with 1000BASE-T.
*2. You can use either of cables when not using EtherCAT or when using EtherNet/IP with 100BASE-TX or
10BASE-T.
4 - 46
Power
lines
Controller
200 mm
Equipoten-
tial bonding
system
Recom-
mended
Recom-
mended
Recom-
mended
Metal tubing
Ground to 100 Ω or less
Earthing methods
Star earthing
Connecting
Connecting
devices and
devices and
noise sources
noise sources
to separate
to a common
earth elec-
earth electrode
trodes
Recommended Not recom-
mended
Recommended Not recom-
mended
Recommended Not recom-
mended
NX-series CPU Unit Hardware User's Manual (W535)
Daisy chain
Not recom-
mended
Not recom-
mended
Not recom-
mended