Earthed or Unearthed Cables?

When you say "earthed" do you mean screened (like a coaxial cable with the screen providing an earth function), armoured (like a coaxial cable but steel (or similar) strands providing mechanical protection), or earthed (as in the three phase cable also includes an earth wire).

The answer depends on which country this site is in (and local electrical regulations and standards). I suggest you consult them first for the answer that is applicable to you, better yet as this is an industrial application ask your site electrician.

This subject was discussed many times earlier in CR4 . Better read the previous threads on the subject.

http://cr4.globalspec.com/comment/318579

The selection of earthed/unearthed cable will depend on your system. If your distribution system is earthed then you have to use cable manufactured for earthed system. (which the manufacturer specifies). If the system is unearthed then you need to use cable manufactured for un earthed system.The unearthed system requires high insulation level

Hope yo get your answer..