Wiring Safety And Noise Controls - Omron CP1H-X40D Operation Manual

Wiring CP1H CPU Units
3-4-3

Wiring Safety and Noise Controls

I/O Signal Wiring
Inductive Loads
Note
Noise from External
Wiring
Whenever possible, place I/O signal lines and power lines in separate ducts or
conduits both inside and outside of the control panel.
(1)
(2)
Suspended duct
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.
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.
IN
Diode
DC input
L
COM
Use surge suppressors and diodes with the following specifications.
Surge Suppressor Specifications
Resistance: 50 Ω
Capacitance: 0.47µF
Voltage: 200 V
Diode Specifications
Breakdown voltage:
Mean rectification current: 1 A
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)
In-floor duct
OUT
Relay output
Surge suppressor
COM
OUT
Relay output or
transistor output
COM
3 times load voltage min.
Section 3-4
(1) = I/O cables
(2) = Power cables
(1) (2)
Conduits
L
+
Diode
125