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(d) When the main circuit line and power line cannot be
separated, use a shielding cable and ground it on the
programmable controller side.
However, ground it on the opposite side in some cases.
Programmable controller
Input
Output
(e) When cables are run through pipes, securely ground the
pipes.
(f)
Run the 24VDC input line away from the 100VAC and 200
VAC lines.
(g) The cabling of 200m (656.2ft.) or longer distance may produce
leakage current depending on the capacity between lines and
result in an accident.
(h) As a countermeasure against the power surge due to lightning,
separate the AC wiring and DC wiring and connect a surge
absorber for lightning as shown in (i) of item (1).
Failure to do so increases the risk of I/O device failure due to
lightning.
(3) Grounding
(a) Carry out the independent grounding if possible. (Grounding
resistance 100Ω or less.)
(b) If the independent grounding is impossible, carry out the
shared grounding (2) as shown below.
Other
Programmable
device
controller
Class 3
grounding
(1) Independent grounding.....Best
(c) Use the cable of 2mm
Set the grounding point closer to the programmable controller
to make the grounding cable short as possible.
(d) If a malfunction occurs due to earthling, separate either LG or
FG of the base module, the device combination, or all the
connection from the earthling.
Shielded cable
Shield jacket
DC
Other
Programmable
controller
device
Class 3
grounding
(2) Shared grounding.....Good
2
or more for grounding.
44
RA
Other
Programmable
controller
device
(3) Common grounding.....Not allowed
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