Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 208

Wiring Methods
Grounding Long-distance Expansion Racks
172
Other equipment
CS1D PLC
LG
GR
Ground
(100 or less)
Other equipment
CS1D PLC
LG
GR
Ground
(100 or less)
• Do not share the PLC's ground with other equipment or ground the PLC
to the metal structure of a building. The configuration shown in the follow-
ing diagram may worsen operation.
CS-series PLC Other equipment (motor, inverter, etc.)
A difference in potential will occur between remote ground points if more than
one point is grounded on the CPU Rack and Long-distance Expansion Racks
in a CS1 Long-distance Expansion System. This is caused by high-frequency
noise from power lines, potential and phase differences between power lines,
and other factors. To prevent noise from entering on the GR (ground) terminal
as a result of a difference in potential, wire the system as shown below.
• Connect all of the GR terminals on the Racks and ground them at one
point only to 100
• Short the LR terminals to the GR terminals.
• Use a ground wire of 2 mm
• Insert 1:1 isolating transformers into the power supply lines and do not
ground the secondary sides of the transformers.
GR
Ground
(100 or less)
GR
Ground
(100 or less)
or less.
2
min.
Section 5-4