TIA/EIA-568 Patch Cabling Length Limits Explained

cablecablinglayer1standardisationt568b

[Light edits to emphasise versions]

What are the exact requirements of TIA/EIA 568 cabling standard as regards to the length of patch/work area cables?

Specifically, I see from my 2001 copy ANSI/TIA/EIA-568-B.1-2001, Section 6.4.1.4 "Maximum lengths for copper cabling" has formulas for total length of cable against lengths of work area cable and patch cable, with deratings for various thicknesses of stranded cable. Table 6.1 shows patch + work area cables up to 27 m, shown against reduced horizontal cable lengths down to 70 m.

My understanding was thus it was within standard to have longer stranded cords at the ends if you have shorter horizontal lengths.

But I'm also told that certification authorities such as BICSI in the US require patch + work area cords to be no longer than 10 m.

Or are there additional documents from eg BICSI certifications that should also apply? Or have I misread 568 somehow?

EDIT

  • The same material about cable lengths appears in ANSI/TIA-568-C.1 (2009),
    as section 9.4.2.4.1.
  • The current version of ANSI/TIA-568 D, from 2015

Best Answer

I believe you are looking at a table that is specific to a MUTOA, which is a special case.

What the ANSI/TIA/EIA 568 Commercial Building Telecommunications Cabling Standard says for the general case is:

Cable Length

The maximum distance between the telecommunications outlet and the horizontal cross connect shall be no more than 90 meters. The maximum length of all patch cords and jumpers in the telecommunications closet shall be no more than 5 meters, and the total length of all patch cords both in the telecommunications closet and at the work area shall be no more than 5 meters.

-also-

Work Area Cords

The maximum length of a work area patch cord is 5 meters. Generally, the patch cord will have similar connectors on each end. If additional devices are required, such as adapters, they will not be part of the horizontal cabling system, but rather be connected via the patch cord.

-also-

Channel and Permanent Link Definitions

The Channel is defined as the 90 meters of horizontal cable, the telecommunications connector and patch cord in the work area as well as 2 connectors and a maximum of 2 patch/equipment cords in the telecommunications room. The maximum allowable length of patch cords and equipment cords is 10 meters. Also included in the channel is an optional transition or consolidation point.

-also-

Work Area Cords

Work area cords are limited to 5 meters as per subclause 4.3 of the original documentation. Work area cords shall meet or exceed the requirements of ANSI/TIA/EIA-568-B.2 for Category 3 and 5e, and ANSI/TIA/EIA-568-B.2-1 for Category 6 and ANSI/TIA/EIA-568-B.3 or ANSI/TIA/EIA-568-B.3-1.

That means that you can have a maximum of 10 meters of patch cable in a channel.

Related Topic