How To Wire Shielded Cable?

[KidViciou$]

is there anything i need to do specifically to wire solid shielded cat6 cable that will be in wall, and wired to a keystone jack?

thanks

 

[ScottMac]

Yes.

You have to use components designed for shielded cable for the entire span. You also need to use shielded jumpers. The ground (connected to the central distribution point) should be a single-point that's bonded to the facilities ground.

Failure to properly ground the shield and carry the shielding throughout the system will result in cabling that rates somewhere just above barbed-wire fence material (unrated ... actually worse than unrated, since it will collect noise from the environment).

Good luck.

Scott


Edit: Actually, you can use regular UTP jumpers ....

 

[KidViciou$]

thanks for the reply, but could you please provide some links to the materials i will need? i'm not 100% sure, this sounds more complicated than what i expected

 

[spidey07]

The real question is "why would you use shielded cable?"

Its notoriously difficult to get right (see Scott's description) and expensive.

 

[KidViciou$]

because i'm running it in the wall within 1 foot of powercords, at distances > 150 feet

therefore solid unshielded didn't seem like a good option for me

 

[ScottMac]

The quality of today's UTP, coupled with better transceiver technology and design, minimize that kind of interference to a vitrual nil.

One foot from an AC source is no big deal. It would be nearly impossible to run cabling today and NOT be within one foot of SOME kind of AC souce along the way. All Category-rated cabling is good for ~100 meters (~108 Yards, ~325 feet) shielded or not. Unshielded Category-rated cabling meets exactly the same specs as the Shielded stuff (same Cat spec).

I can pretty much guarantee that improperly terminated shielded cable (or a mix of shielded and unshielded components on shielded cabling) will do you much worse. It will be no better than common phone wire (no Category rating), probably worse ... depending on how / how much you violate the specs.

For example, if you do not ground the shield properly, the shield will act as an antenna and collect common-mode noise (60 Hz). If you don't ground it properly (single point to the facilities ground), you run the risk of a ground loop and enhanced 60Hz (and other environmental noise) collection.

Keep in mind that shielded cable (actually "Shielded" UTP is called "Screened" (because otherwise you'd have "Shieled Unshielded Twisted Pair") was designed and built for that screening to assist in reducing the interference .... even if the (improperly terminated) shielding didn't contribute to the noise reduction, the wire pairs within are not built to a configuration that can function as welll as cabling designed to work without shielding.

Screened / shielded cabling also operates at a different impedence (~120 - 150 ohm versus ~100 for UTP). You losses / attenuation will be higher if not properly terminated (reduces the ACR - Attenuation-to-Crosstalk Ratio - a very bad thing).

IMHO, If you've already run the cabling, your best bet is to use it to pull in standard UTP of whatever Category rating you desire. The cost difference in components and potential performance problems aren't worth whatever you already spent.

FWIW

Scott

 

[spidey07]

I "think" spec for category 5 or greater wire is 3" from 120 volt sources.

Its only when you get into 400 volt stuff that you might want to be further away.

 

[KidViciou$]

darn, this sux, well it's a good thing the company originally sent me utp cat6 even though i ordered sutp cat 6

i will now tell them i'll keep the utp, and send back the sutp, and save about $50

thanks for all the advice guys, and saving me a lot of extra heartache

 

[spidey07]

anytime,

We'd hate to see you go through all that trouble when it might not be needed. Its hard enough getting CAT6 right, let alone adding shielding to it.

 

[fargus]

An easier solution would be to run your cable through conduit in the areas where it comes closer than you'd like to power.

 

[KidViciou$]

i just thought abotu this, couldn't i ground the cable by connecting it to the ground of an ac outlet?

 

[ScottMac]

No.


-Scott

 

[KidViciou$]

okay thanks, do you have any elaboration as to why the grounds would be different? (i'm not an electrician when i hear ground, i think of them as all being the same)