Can I use foiled cable without earthing it?

PhilthyPhil · 14 Nov 2012 at 20:02

I ordered some cat 6 cable and have been sent cat 6e. I didn't realise this stuff existed, I have only come across 6a before where the pairs are foiled individually. This stuff just has foil under the jacket covering all the pairs. Anyway, can I just use this the same as normal cat 6 and not connect the foil to anything without causing any problems?

Awahwah · 14 Nov 2012 at 21:30

Yes, but it wouldn't pass a Test. Guessing this isn't a Professional install?

bremen1874 · 14 Nov 2012 at 21:34

From a standards point-of-view cat6e doesn't exist (AFAIK), it's meaningless and the cable could be almost anything (not necessarily bad).

I believe that without proper grounding all the screening can do is work as an antenna for potential interference.

PhilthyPhil · 14 Nov 2012 at 21:36

bremen1874 said:
I believe that without proper grounding all the screening can do is work as an antenna for potential interference.

This is what I'm worried about. That having the foil there without earthing it is worse than not having it at all...??

bremen1874 · 14 Nov 2012 at 21:49

PhilthyPhil said:
This is what I'm worried about. That having the foil there without earthing it is worse than not having it at all...??

Even if it is worse I don't think you'll have any problems. You quite regularly see people successfully using screened cable for home installations just because they think it's better.

I'm going on something I was told years ago by someone who should have known what they were talking about, but it's quite possible they were just repeating in turn what they'd heard.

I tried to research this a couple of years ago and found a variety contradictory opinions. I've ducked out and stuck to using UTP.

J.B · 15 Nov 2012 at 09:40

I was always under the impression that if you dont earth it then it acts as an antenna but my basic knowledge of physics would tell me that that would only occur if you grounded one end but not the other?

Either way, I've used shielded cable and didnt ground it at either end because the numpty that ordered it didnt get shielded faceplates! That was about 20 runs over 20m and there's wasnt any problems.

Yamahahahahaha · 15 Nov 2012 at 10:42

Uses of FTP are limited and probably not worth specifying unless:
1) The cabling engineer recommends it due to a stretch beside high power cable (multiple 30A 240v lines or triple phase power).
2) There are known significant sources of radio signals nearby. For instance you might be near a broadcasting tower.

These days, you would typically run fibre in both these situations.

As far as 'foil done badly' goes: Without grounding you'll be inducing your own noise into the foil, which would make it worse than using UTP in a best case scenario.