Omron NX-PA Series User Manual page 137

a) Connecting devices and noise sources to separate earth electrodes
This is an earthing method to separately ground an earth electrode of the device that is con-
nected with a communications cable or other devices and an earth electrode of a high-power
device that could be a noise source, such as a motor or inverter.
Each earth electrode must be ground to 100 Ω or less.
Connect the ground lines of the device that is connected with a communications cable and other
devices as a bundle to a single earth electrode. Be sure that the earth electrode is separated by
a minimum of 10 m from any other earth electrode of a device that could be a noise source.
Control panel
b) Connecting devices and noise sources to a common earth electrode
This is an earthing method to connect the device that is connected with a communications cable,
other devices, and a device that could be a noise source, to a common earth electrode.
This earthing method is not recommended because the device that could be a noise source may
interfere electromagnetically with other devices.
Control panel
 Daisy Chain
This is an earthing method to connect the device that is connected with a communications cable,
other devices, and a device that could be a noise source using a daisy-chain topology to a common
earth electrode.
This earthing method is not recommended because the device that could be a noise source may
interfere electromagnetically with other devices.
NX-series CPU Unit Hardware User's Manual (W535)
Other device NX-series CPU Units
Hub
Other device NX-series CPU Units
Hub
A device that could be
NX-AUX01 a noise source
PLC
10 m min.
A device that could be
NX-AUX01 a noise source
PLC
4 Installation and Wiring
4
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