APPX
Appendix 6 EMC and Low Voltage Directives
135
A
Cables extended out of the control panel
Use a shielded cable for a cable extended out of the control panel such as an I/O signal line (including a common line) and
cable for communications.
If a shielded cable is not used or not grounded correctly, the noise immunity will not meet the specified value.
■Grounding a shielded cable
• Ground the shield of a shielded cable as close to the module as possible so that the grounded cable will not be affected by
electromagnetic induction from ungrounded cables.
• Ground the exposed shield to a large area on the control panel. A clamp fitting can be used as shown below. In this case,
mask off the inner wall surface of the control panel, which comes in contact with the clamp fitting.
Do not use the tip of a PVC wire soldered onto a shield of the shielded cable for grounding. Doing so will raise
the high frequency impedance, resulting in loss of the shielding effect.
(1) Paint masking
(2) Clamp fitting
PVC wire
Solderless terminal
Shielded
cable
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