Written by Don Schultz, TrueCABLE Senior Technical Specialist, BICSI TECH, INSTC, INSTF, Fluke Networks Copper/Fiber CCTT Certified
Thin in! “Skinny” patch cords have become very popular and for good reasons. Server racks and network racks in particular see great benefit because these patch cords make wiring much easier. However, there can be some downsides to thin extension cords that you need to be aware of. Nothing in life comes without some kind of trade-off so we’ll talk about the pros and cons of using thin extension cords!
Note that patch cords can also be optical and coaxial. These components are also referred to as “equipment wiring.” In this particular blog, we’re focusing on twisted pair copper patch cords (aka Ethernet), which terminate at both ends of standard 8P8C jacks (aka RJ45s).
What are thin (skinny) patch cords?
Thin patch cords do not have any specific category or color. It can be Cat5e, Cat6, Cat6A and any color you want really. If one were to assign a definition to “skinny” patch cords, it would be…
Thin Patch Cord Definition: Patch cords that are thinner than “typical,” highly flexible, and bend tightly without losing performance, enhancing ease of installation in high-density scenarios or other limited spaces.
The idea is to make equipment racks easier to install, especially with high-density installations. High-density fixtures are likely to be prone to heating issues, so the thinner the patch cord the more airflow you’ll get. These same thin cords are also useful for modular furniture, where there is very little space for cable routing.
Ideal use cases for thin patch cords
Data centers, network closets, and high-density switchboards, short patches between environments where airflow and regulation are priorities
How are skinny patch cords constructed?
There is nothing in the TIA standard that defines what is or is not a thin patch cable. In fact, there’s nothing in the standard that even says how thin you can get. No, instead, the rules of the road around construction are fairly loose and are defined by ANSI/TIA-568.2-E – Standard for Balanced Twisted Pair Telecommunications Cables and Components. The specific section is 5.5 “Mechanical Performance of Rope Cable”.
TIA-specified patch cord construction requirements:
CCA (Copper Clad Aluminum) is not permitted. Conductors may be stranded or solid copper. There must be four balanced twisted pairs (eight conductors total) Conductor gauge may range from 22 to 28 AWG. Connectors must be insulated with thermoplastic. The connectors must be surrounded by a thermoplastic outer shell. Shielded patch cords must withstand 500 bends under specified conditions and still perform as intended.
Note that there is no minimum or maximum overall jacket diameters specified for wire cables. The type of cable jacket (fire rating) is not specified as this depends on the specific installation requirements. Technically, wiring cables don’t even need to be marked with performance class! Pretty loose guidelines, right?
Reality would dictate that you would not achieve what anyone would consider thin wire with 22 AWG and shielded conductors. You will end up with a thick extension cord, despite any hard efforts.
So the implication is that “skinny” ropes are in the eye of the beholder. Generally, thin patch cords are constructed of 28 AWG stranded pure copper conductors, and are generally less than 4.00 mm thick (jacket OD). Shielding is often not used in thin patch wires, since shielding would defeat the entire purpose of thin patch wires being a permissible bend radius and… well… thin.
Beware of very thin patch cords. You will see 30 and even 32 AWG conductor wiring for sale. These ultra-thin ropes are not compliant with standards and are therefore considered counterfeit.
Key Benefits of Slim Patch Cable
Improved airflow in shelves and cabinets Easier cable management and organization Higher port density (more cables in less space) Lighter and more flexible for tight corners
Is there a “standard” patch cord?
Not really, no. However, there is a “generally accepted” patch cord that uses 24 AWG stranded copper conductors. This general acceptance is further supported by the maximum conduit length of 328 feet while using a permanent link with a maximum length of 295 feet (conduits being the permanent link plus patch cord at both ends). Where did this come from? The TIA standard is geared toward commercial buildings and standard floor space sizes, where a typical network wiring closet (called a TR or communications room) is limited to serving 10,000 square feet. Given these parameters, the maximum length of permanently installed “rack-to-socket” copper twisted pair category cable is 295 feet. The maximum permanent link length applies to Cat5e through Cat6A. Solid copper conductor grade cable is used to create this connection, and 22 to 24 AWG can be used.
The 328 feet long part comes in when you use permanent link patch stranded copper patch cords to create your communications channel. Per the TIA standard, 2 x 16.5 feet 24 AWG stranded copper patch cords (33 feet total) are permitted to meet the 328 feet conduit limit. Of course this will take many variations depending on the length of the permanent link and the copper gauge of the patch cords. You can see the downgrade chart at Calculate the total channel length of an Ethernet cable for success.
It goes without saying that the thinner the stranded copper patch cords are the shorter things become. This leads us to the next topic…
Slim patch cord limits
As the stranded copper becomes thinner, the allowable lengths become shorter. However, this is not a “1 for 1” phenomenon. It’s logarithmic! Here are some of the most notable performance limitations you’ll encounter:
You will not reach the maximum allowable conduit length of 328 feet with a 28 AWG patch cord. Due to a maximum solid copper permanent connection length of 295 feet, the maximum conduit length is 315 feet which would be 2 x 10 feet 28 AWG patch cord (20 feet total). The absolute maximum length of 28 AWG patch cord allowed is 49 feet, even if the 28 AWG patch cord is the entire conduit with no permanent bond at all. The bundle size of Power over Ethernet cables has been reduced. Although any 28 AWG patch cord will work with 100W (DC) PoE, there are limitations on how many wires you can group together due to increased heat. Please see The power is over
This table shows how the copper gauge of patch cord, as well as the length of the permanent bond (or no permanent bond at all) affects how far you can go:
TIA-568.0-E Declassification diagram for patch cords. The featured shaft is 28 AWG.
Notes on using this table:
D= Derating factor applied using an equation, so… D=1.0 means solid copper is used for the patch cord, no downgrading D=1.2 means 24 AWG stranded copper patch cord D=1.5 means 26 AWG stranded copper patch cord D= 1.95 means bond 28 AWG stranded copper patch cord = permanent link length
When to skip thin patch cords
You have no intention of using permanent links and want to just run patch cords, but you need to go beyond 49 feet. Large sizes of slim patch cords that carry 30W or higher PoE wattage. Bundles of patch cords that must be installed in conduit and withstand PoE of any electrical strength
What to look for when buying Slim Patch cables
The main concern when making a purchasing decision on patch cords is to not accidentally purchase a fake cord!
The vast majority of patch cords available on the mass market will not pass the certification test. The issue is rather serious.
How dangerous is it? Here is an industry quote, from a reputable source. trueCABLE has confirmed this information with our own testing.
“To get an idea of the quality of equipment wire, the Telecommunications Cables and Telecommunications Association (CCCA) completed extensive electrical performance testing of Category 6 copper patch cords, which tested nearly 500 samples that included 379 wires from outside and lesser-known manufacturers and 120 wires from well-known North American manufacturers. Of the 379 marine lead wires, 322 failed within the electrical performance parameters specified in TIA 568-C.2 standards with 78% failing by a margin of 3 dB or greater and 45% failing by a margin of 6 dB or greater. These wires can potentially cause major network problems once they are included in the conduit. All patch cords from recognized North American manufacturers have demonstrated a 0% failure rate.”- Fluke Networks
What to look for in a slim patch cord:
Select a reputable manufacturer from the start, do not select a patch cord with conductors thinner than 28 AWG, conductors must be pure stranded copper, and the cord must be configured and certified to a specific class at the factory – not just “verified” or “tested” because you don’t know what type of testing has already been done from the UL or cETLus list of cable jacket fire safety factors
conclusion
So this is it! The skinny on the thin patch cords. Thin patch cords are a huge boon for IT staff and even cable system installers, providing a level of flexibility (literally) to create high-density racks and perform installations that would have been difficult to achieve in the past. Keep in mind that you want a patch cord that is rated and approved for the category. Additionally, keep in mind the limitations that can surround thin patch cords and the installation process will be easier to handle.
Happy communication!
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