Grounding - Omron NJ501-1400 User Manual

4 Installation and 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.
Additional Information
• In a country or region where the earthing method is regulated, you must comply with the regu-
lations. Refer to the applicable local and national ordinances of the place where you install the
system, or other international laws and regulations.
• For details on wiring EtherCAT or EtherNet/IP, refer to the NJ/NX-series CPU Unit Built-in Eth-
erCAT Port User's Manual (Cat. No. W505) or the NJ/NX-series CPU Unit Built-in EtherNet/IP
Port User's Manual (Cat. No. W506).
• Ethernet switches are used with the EtherNet/IP. For information on the environmental resis-
tance of the Ethernet switch to use, the grounding between Ethernet switches, or the specifi-
cations of cables, ask the Ethernet switch manufacturer.
4-56
Earthing methods
Star earthing
Connecting
Equipoten-
devices and
tial bonding
noise sources
system
to separate
earth elec-
trodes
Recom- Recommended
mended
Recom- Recommended
mended
Recom- Recommended
mended
NJ-series CPU Unit Hardware User's Manual (W500)
Connecting
devices and
Daisy chain
noise sources
to a common
earth electrode
Not recom- Not recom-
mended mended
Not recom- Not recom-
mended mended
Not recom- Not recom-
mended mended