Electrical Environment - Omron NX Series User Manual

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.
Refer to 4-4-2 Grounding on page 4-31 for details on the grounding of the Controller.
Considerations for Earthing Methods
Local potential fluctuations due to lightning or noise occurred by power devices will cause potential
fluctuations between ground terminals of devices. This potential fluctuation may result in device mal-
function or damage. To prevent this, it is necessary to suppress the occurrence of a difference in elec-
trical 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 ca-
*1
ble
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.
NX-series CPU Unit Hardware User's Manual (W535)
Power
lines
Controller
200 mm
tial bonding
Recommend-
ed
Recommend-
ed
Recommend-
ed
Metal tubing
Ground to 100 Ω or less
Earthing methods
Star earthing
Connecting
Equipoten-
devices and
noise sour-
system
ces to sepa-
rate earth
electrodes
Recommend-
ed
Recommend-
ed
Recommend-
ed
4 Installation and Wiring
Connecting
devices and
noise sour-
Daisy chain
ces to a
common
earth elec-
trode
Not recom- Not recom-
mended mended
Not recom- Not recom-
mended mended
Not recom- Not recom-
mended mended
4-43
4