Low voltage control cables 1

[qualitypro]

Do LV control cables have to be shielded? What is the downside if these are not shielded?

 

[DHambley]

That's kind of a broad question but, if the wires are within E & M fields which could distort the data on the LV wires, then yes, shielding is required. Can you tell us what kind of environment these cables are in?

 

[DRWeig]

Also, what are you using the cables for?

There is no code or rule that says they need shielding, it depends on the application.

Best to you,

Goober Dave

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[qualitypro]

These cables are used throughout in a power project but these are not the 300V instrumentation shielded cables. Does anybody know what is the IEC 60754 Part-2 calls for?

The spec states the below,
LV Control cable shall be 0.6/1kV grade, and have stranded annealed copper
conductors of at least 1.5 sq. mm size, extruded PVC Insulated, extruded FRLS
PVC outer sheathed. Control cables shall be screened and grounded to eliminate
any spurious voltage pick-up. Cable shall comply with IEC 60754 Part-2.

 

[mcgyvr]

IEC 60754-2
Test on gases evolved during combustion of materials from cables -

 

[MikeHalloran]

"Screened and grounded" sounds a lot like a shield.

My friends on oil rigs also like to see external armor braid to protect the insulation and shield from falling wrenches and such.




Mike Halloran
Pembroke Pines, FL, USA

 

[jraef]

Yes, "screened" is exactly what we here in the US call "shielded". Grounded by the way means grounded at only one end.

Interesting that the specifier used the IEC term screened instead of shielded, but then used "grounded", a typically ANSI term, instead of "earthed". Or in IEC terminology, does grounded mean something different from earthed?

"Will work for (the memory of) salami"