Omron NA-series, Руководство пользователя

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3 Installation and Wiring
NA-series Programmable Terminal Hardware(-V1) User’s Manual (V125)
3-5
Con
trol Pan
el In
st
alla
tion
3
3-
5-6 Gro
undin
g
Grounding has the following two purposes.
• Protective Grounding
Protective grounding is done to ensure safety. It is intended to prevent electrical shock by holding the
electrical potential at the grounding potential that is generated by factors such as leakage, induction,
or failure.
• Functional Grounding
Functional grounding is done to protect device and system functions, including prevention of noise
from external sources, or prevention of noise from devices or equipment that could have harmful
effects on other devices or equipment.
The functional ground must in some cases be determined by experimentation. It is important to suffi-
ciently check the particular circumstances before grounding.
 Wiring the Ground
The NA unit has a protective ground terminal ( ) and a functional ground terminal ( ).
1. Protective Ground
For safety, be sure to use a ground of 100
Ω
or less for the protective ground of the NA unit. For
the grounding wiring, refer to 3. Grounding Wiring on page 3-20.
• Applicable Wire
• Screw Tightening Torque
1.0 to 1.2 N·m
3-5-6 Grounding
Grounding Methods and Precautions
Conductor cross-section
2.00 mm
2
min.
24VDC 24VDC
+
-
Protective ground terminal
SD SD SD