Omron CP1H CPU UNITS - PROGRAMMING 05-2007, Operation Manual

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Wiring CP1H CPU Units
Section 3-4
3-4-3 Wiring Safety and Noise Controls
I/O Signal Wiring
Whenever possible, place I/O signal lines and power lines in separate ducts or
conduits both inside and outside of the control panel.
If the I/O wiring and power wiring must be routed in the same duct, use
shielded cables and connect the shields to the GR terminal to reduce noise.
Inductive Loads
When an inductive load is connected to an I/O Unit, connect a surge suppres-
sor or diode in parallel with the load as shown below.
Note Use surge suppressors and diodes with the following specifications.
Noise from External
Wiring
Take the following points into account when externally wiring I/O, power sup-
ply, and power lines.
• When multi-conductor signal cable is being used, avoid combining I/O
wires and other control wires in the same cable.
• If wiring racks are parallel, allow at least 300 mm between the Racks.
(1)
(2)
(1) (2)
(1) (2)
Suspended duct
In-floor duct
(1) = I/O cables
(2) = Power cables
Conduits
L
IN
COM
OUT
COM
OUT
COM
L
+
Diode
DC input Relay output
Surge suppressor
Relay output or
transistor output
Diode
Surge Suppressor Specifications
Resistance: 50
Ω
Capacitance: 0.47
µ
F
Voltage: 200 V
Diode Specifications
Breakdown voltage: 3 times load voltage min.
Mean rectification current: 1 A