Warren and Brown Technologies (WBT’s) range of high-performance, mini (reduced diameter) patch cords, also known as slimline patch cords, have been successfully deployed in countless data networks. The term ‘mini’ refers to the smaller OD, obtained by using 28 AWG copper conductors, rather than the typical 24 AWG copper conductors used in regular patch cords, thereby reducing the patch cord outside diameter. The use of mini patch cords in today’s high-speed networks, provides a number of key operational and performance advantages, especially at workstations and in data racks. When specifying these smaller diameter patch cords, it is important that due consideration is given to the technical differences between mini patch cords and regular diameter patch cords, to ensure that the link performs at its optimum.
WBT has 2 types of mini (reduced diameter) patch cords available:
Mini CAT6 U/UTP patch cords (CAT6 unshielded patch cords) are more than 55% lighter, 50% smaller in cross-sectional area and provide more than 40% tighter bend radius when compared with standard Category 6 (CAT6) patch cables.
Mini CAT6A U/FTP patch cords (CAT6A shielded patch cords) are approximately 15-20% smaller in diameter and more flexible, when compared with standard Category 6A (CAT6A) patch cables.
WBT mini-patch cords simplify routing, saving time and reduce crowding in racks, improving airflow to critical equipment. By reducing congestion inside racks and along pathways, WBT mini cords allow faster cable identification and patching in high capacity racks.
WBT mini patch cords are the smallest and lightest patch cables available and provide full application support for Category 6 and 6A channels when designed and installed following the guidelines in this technical discussion paper. A channel with a total of up to 6 meters of the mini cord can be used in combination with a 90-metre permanent link to deliver full CAT6 and CAT6A applications support. Patch cords of even greater length can be installed but must be used in combination with shorter permanent link lengths than the 90-metre maximum specified in standards.
While these features offer significant benefits in terms of operational savings, there are a number of technical limitations that must be acknowledged when undertaking deployment of mini cords.
Standards and the mini (slim) patch cords
The ISO/IEC and the TIA standards describe the use of patch cords between 22 and 26 AWG. The use of a smaller conductor means higher attenuation, particularly at higher frequencies. To accommodate this higher attenuation, WBT recommends using a derating factor of 1.9 compared to a 24 AWG stranded cord when designing channels using the WBT 28AWG mini cords.
The following limitations are what WBT specify for a mini cord design:
SCENARIO 1 – Channel Length = 100 Metres (while this is possible, it is not recommended)
Permanent Link length – 98 metres (beyond all standards recommendations of a 90 metres maximum)
Total maximum 28 AWG patch cord length – 2 metres
SCENARIO 2 – Channel Length = 96 Metres
Permanent Link length – 90 metres
Total maximum – 28 AWG patch cord length – 6 metres
SCENARIO 3 – Channel Length = 93 Metres
Permanent Link length – 83 metres
Total maximum – 28 AWG patch cord length – 10 metres
In practice, WBT would advise against using scenario 1. Although it is true that it does satisfy the current application requirements, it is really a case of two wrongs don’t make a right in terms of standards compliance. There is a risk, albeit small, that a new application comes out during the lifecycle of the cabling and a >90metre link length will not work. In reality, the number of situations where a link length of 90 metres or more is required, would be a fraction of 1% of all projects.
In terms of POE applications across mini cords, WBT specifies a maximum bundle size of 24 cables to assist in limiting the temperature increases in the cables associated with delivering POE deployments. Current standards work limits the maximum temperature increase to less than 15 degrees Celsius above ambient for the centre cable in a bundle.
On a practical implementation level, the higher power levels mentioned here will most likely be associated with changes to workplace health and safety requirements and device-level power management to limit the potential risks associated with high power arcing. The table below provides guidance on the maximum mini cord and link lengths that WBT would recommend;
|Total 28 AWG Patch Cord length||Total Permanent Link Length||Total Channel Length|
*These link lengths are not standards compliant and not recommended by WBT.
As with any installation using copper conductors, it is important to consider the annual temperature ranges for each project location. The lengths shown in the above table refer to an ambient temperature of 20°C. The maximum lengths of patch cords shown in the table above can be maintained at ambient temperatures out to 60°C. However, in these high-temperature environments, the length of the Permanent Link may need to be reduced according to the temperature and cable length.
For more information on our HypaConnect integrated cabling solutions contact Warren and Brown Technologies on [email protected].