3 to achieve better emc protection, To achieve better emc protection, Additional installation tips – Beijer Electronics iX Panel TA150 EN User Manual

Page 18: Use shielded cables for rs232 communication, Connect the shield at both ends

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Additional Installation Tips

6.3 To Achieve Better EMC Protection

Initially, use the original cabling from Beijer Electronics primarily.

Use shielded cables for RS232 communication.

Use twisted pair and shielded cabling for RS422 and RS485.

Use the cabling intended for the bus type; Ethernet, Profibus, CC-Link,
CAN, Device Net etc.

Install and connect according to applicable specifications for the relevant bus
standard.

Use shielded cabling for Ethernet, preferably with foil + braided shield.

D-sub covers should be shielded, and the shield should be connected to the
cover 360 ° where the cable comes in.

Connect the shield at both ends.

Shielded cable

Not same potential

Ground plane 1

Ground plane 2

Ground plate

Ground plate
in another building

0.1 uF/250 V

5352

With longer distances, there is a risk that the ground potential may be different.
In that case, the shield should only be connected at one end. A good alternative
is to connect the other end of the shield to the ground via a 0.1 uF/250 V plastic
capacitor. Both ends are then connected to the ground in terms of HF, but only
connected to the ground at one end in terms of LF, thus avoiding the 50 Hz
grounding loops.

Metal cabinet

Metal cabinet

Terminal or connector

Terminal or connector

EMC cable gland

Plastic cable gland

Shielded cable

Shielded cable

Short distance

Cable clamp
in steel

5353

1. Use an EMC cable gland or regular plastic cable gland, remove the outer jacket

and connect the shield to the installation plate with a 360 ° metal cable clamp.

2. Place the 24 V DC and communications cabling in one cable trunk/cable duct

and 230/380 V AC in another. If the cables need to be crossed, cross them at
90 ° only. Avoid combining the cabling for stronger 24 V DC outputs with
the communication cabling.

Ferrite cores that are snapped onto the shielded cabling may remove minor
disturbances. Large ferrite pieces that are snapped onto unshielded cabling and
where the wires go 2-4 times around the cores are approximately 5-25 times more
efficient.

Beijer Electronics, MAEN011A

18

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