Appendix; Cables - Mitsubishi Electric Q26UD(E)HCPU User Manual

Appendix 8.1.3

The cables extracted from the control panel contain a high frequency noise component. On the outside of the control
panel, therefore, they serve as antennas to emit noise.
To prevent noise emission, use shielded cables for the cables which are connected to the I/O modules and intelligent
function modules and may be extracted to the outside of the control panel.
The use of a shielded cable also increases noise resistance.
The signal lines (including common line) of the programmable controller, which are connected to I/O modules,
intelligent function modules and/or extension cables, have noise durability in the condition of grounding their shields by
using the shielded cables. If a shielded cable is not used or not grounded correctly, the noise resistance will not meet
the specified requirements.
(1) Grounding of shield section of shielded cable
• Ground the exposed shield section of the shielded cable close to the module. Confirm that the grounded
cables are not induced to electromagnetic from the cables, which are not yet grounded.
• Ground the exposed shield section of the shielded cable to large area on the control panel.
A clamp fitting can be used as shown below.
In this case, apply a cover on the painted inner wall surface of the control panel, which comes in contact with
the clamp, to prevent the surface from being painted.
Shield section
Note) The method of grounding with a vinyl-coated wire soldered onto the shielded section of the shielded
cable as shown below is not recommended. Doing so will raise the high-frequency impedance,
resulting in loss of the shielding effect.

Cables

Shielded cable
Wire
Solderless terminal, crimp contact
Screw
Paint mask
APPENDICES
Clamp fitting
Shielded cable
655
A