Cat5e cable sheath stripping

[rsmadhava]

I understand that while terminating a CAT5e cable, the cable pair untwist should be kept minimum (typically 13mm). Is there any similar guideline for stripping of outer sheath of the CAT5e cable ? Is that just an industry practice or documented in any standard ?

 

[franklin97355]

The twist is part of the documented standard. You should not strip the jacket back any more than absolutely needed.

 

[DTSMAN]

Search this forum. This has been addressed before. I actually started one of the threads on this because I have seen it stripped back to where it enters the punch down (4-6 inches). I have one site I did this way because I need it to be flexible with out pulling wires loose and have not had any problems and this is server client setup with constant communications. I have searched high and low for offical documentation on this but haven't found it. It always only refers to the untwisting of the pairs. I beleive Daronwilson mentioned in one thread that it is best to keep the 4 pairs tight in the sheath as much as possible to eliminate NEXT. Don't quote me on this. That kind of makes sense, but again I have a shortcut to the EIA\TIA website and I have searched the web and haven't found documentation on sheath stripping myself. If anyone can help the both of us with this that would be great.

 

[JBeav]

TIA/EIA-568-B.1 and BICSI manuals call for removing only enough cable sheath as necessary to terminate the cable pairs on the connecting hardware. The connecting hardware manufacturer’s instructions for cable sheath strip-back shall be followed. When terminating category 5e and higher cables, the cable pair twists shall be maintained to within 13 mm (0.5 in) from the point of termination. For best performance when terminating cable on connecting hardware, the cable pair twists should be maintained as close as possible to the point of termination.

Jeff

 

[abscomm]

Cable pair untwist could lead you to assume that as long as each individual pair is twisted then the length of unsheathed cable pairs does not matter.......WRONG, WRONG, WRONG. The sheath plays a very important role keeping the individual pairs correctly alligned with one another. Keep cable sheath removal to a minimum.

 

[rsmadhava]

Thanks for all replies. If any of you find a documented recommendation on this, please post it.

 

[franklin97355]

JBeav mentions two documents and quotes one of them for you.

 

[DTSMAN]

Here is a website with some basic instruction.

http://www.swhowto.com/CAT5_Ch1.htm

 

[JBeav]

The BICSI Installation manual stresses the importance of "minimal sheath removal" but goes further by defining the length of not only un-twisting of pairs but also sheath removal. It instructs to stop the insulation (end of sheath) app. 1/2" from the cable's closest terminated pair. So depending on how the cables are routed, this could be 1/2" from the 1st, 4th or middle pairs.

Jeff

 

[rsmadhava]

While maintaining a distance of 1/2" is possible with 8 position jacks, I am finding it more difficult to do that in IDC modules like Krone LSA and High band modules. Is there any seperate standard for removal of sheath for terminating on IDC modules (8 pair or 10 pair) ?

 

[JBeav]

While it is possible to maintain 1/2" sheath removal on 8p8c jacks, 66, 110, BIX and other Krone blocks, the LSA Highband required (per BICSI Installation manual) maintaining pair twist to within 3/4" of termination. Obviously this would mean more than 1/2" of sheath removal. Routing from the back, feeding conductors through wire guides and terminating on the front would not allow for any less sheath removal that this. One can only assume/trust that with the LSA Highband being cat5, 5e and 6 compliant, that this much sheath removal and untwisting of pairs is not a concern. You need to get in touch with Krone for the answers.

Jeff

 

[PhoneGuy2000]

Jeff (JBeav) is right. The actual wording states no more than is necessary and to follow th e manufacturers rules. All the major manufacturers have websites with white papers describing their requirements. Case in point, on a Bix block, the instructions say to strip back 17 inches of jacket to start. When you are finished, there is about 8 to 10 inches on jacketless cable. Each situation will be different depending on the hardware and the cable performance you want to achieve. The jacket of the cable adds capacitance to the cable and keeps it separated from other cables to minimize "alien" crosstalk.

In short, tried to find the manufacturer's website and get the info.