Omron NX701-1620, User Manual

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4 Installation and Wiring
NX-series CPU Unit Hardware User’s Manual (W535)
4-4 Wiring
4
4-
4-2 Gro
unding
• When you ground the LG terminal or connect the LG terminal with the GR terminal, it may cause to
enter noise into devices or equipments. In this case, do not ground the LG terminal or connect the LG
terminal with the GR terminal.
• Ground the GR and LD terminals with a ground resistance of less than 100 Ω using a 14-gauge wire
(minimum cross-sectional area of 2 mm
2
).
• The ground wire should not be more than 20 m long.
• When wiring an AC Power Supply Unit, if one power supply phase of the equipment is grounded,
always connect the grounded phase to the L2/N terminal.
Precautions for Safe Use
If the LG and GR terminals are connected, make sure to connect them firmly. The LG terminal
that is a noise-filtered neutral terminal, has a half electrical potential of the input voltage. There-
fore, if you touch the metallic part of the LG terminal, GR terminal, or Controller, while the GR
terminal is not grounded, it may result in electrical shock even when a normal operation is per-
formed.
When using the DC Power Supply Unit, you can omit grounding the ground terminals.
• If the DIN Track is made of steel and its surface is not insulated.
If the surface of the DIN Track is treated to produce an insulating material (e.g., anodized aluminum), the DIN
Track contact plate will not be electrically connected to the DIN Track even if they are in physical contact.
Refer to 4-5-6 Grounding on page 4-47 for details on the grounding of the control panel.
Power Supply Unit
Power supply
input terminal side CPU Unit side
Power supply
input terminal
LG GR
L1
L2/N
Power Supply Unit
Ground terminal
Ground
DIN Track
Electrically connected to the DIN Track
through the DIN Track contact plate.