Cable-Tying with Waxed Twine
beaulieu at shell2.xcom.net
Thu Jan 25 04:41:22 UTC 2007
> The other thing I found interesting; The use of Zip Ties on Copper Cabling
> is frowned upon by BICSI. Velcro preferred.
> Something to do with the compression on a twisted-pair cable caused by
> over-tight nylon cable ties screwing with their twist rates, and thus
> changing their Crosttalk characteristics...
For starters, the stuff that Dan Mahoney is looking for is properly known as
waxed linen lacing cord. In a past life I used to order the stuff made
by Ludlow Textiles through Graybar, their part # back then was 89039323. It's
not always in stock in individual stores.
As for plastic ties (TyRap is the brand name for the Thomas & Betts version)
they may be easy to use, but they do have several functional drawbacks,
1) difficulty in maintaining consistent tension from tie to tie, and as
a correlary it is comparatively easy to overtighten one, risking
compression-related damage to the underlying cabling, or as mentioned above,
increasing crosstalk when using twisted-pair cables
2) can harden and/or become brittle over time, eventually failing under stress
3) typical background vibration causes them to tend to chafe the sheaths of the
wiring that the ties are in direct contact with, over a period of years.
Lacing is a lot slower than using platic ties, and doing it is rough on your
fingers. If you're lucky you know a data tech who can show you how to do it
properly, it's really not something that you can just describe in writing.
Depending upon the specific need, contact points may also have pieces of fish
paper laced to them before the wiring is laid out and laced into place.
Not unusual to see this when DC power cables are being secured.
More information about the NANOG