Will 28 AWG Wire Work with Power over Ethernet (PoE) and How?
Power over Ethernet (PoE) technology simplifies enterprise and data center building infrastructure, enabling power delivery over copper Ethernet cables to provide data connectivity and power supply with a single cable. However, when designing structured telecommunications cabling systems for PoE, you might think, can thin Ethernet cables such as 28 AWG wire work with PoE? This article answers this question and also explained what 28 AWG wire is and how to deploy 28 AWG wire for PoE.
What Is 28 AWG Wire
When shopping for Cat5e, Cat6, or Cat6a network cables, you might notice an AWG description printed on the cable jacket such as: 28AWG, 26 AWG, or 24AWG. AWG stands for American wire gauge, a system for defining the diameter of the conductors of a wire which makes up a cable. The larger the wire gauge number, the thinner the wire and the smaller the diameter (for example, 24 AWG - 0.0201 inches, 26 AWG - 0.0159 inches, 28 AWG - 0.0126 inches). Compared to 24 AWG patch cords, 28 AWG patch cords are more than 50% smaller in diameter. What's more, unlike 24AWG Ethernet cables, thinner 28 AWG Ethernet cables enhance the airflow in high-density racks and could be installed easily in compact spaces. The picture below shows the difference between 24 AWG, 26 AWG, and 28 AWG cables.
Can 28 AWG Wire Work with PoE
With all types of devices now connecting to networks via PoE cable, from wireless AP to surveillance cameras, a new question about 28 AWG patch cords started to arise: Can 28 AWG slim cables be used in PoE applications? Before answering this question, there are a few important factors you have to keep in mind:
First, a thinner cable also means a smaller conductor;
Second, using a smaller conductor to send power through a cable via PoE means that more heat is generated and extra heat must be compensated for;
Attributed to their smaller size, thin cables are also closer together when they’re in a bundle, making it even easier for heat to build up. Too much heat negatively impacts cable performance and can cause the temperature of a cable to exceed its jacket rating;
The good news is that it has been verified that 28 AWG wires can be used to support power delivery. According to TSB-184-A-1, an addendum to TSB-184-A: 28 AWG patch cabling can support today’s higher PoE levels, up to 60W. For applications requiring the power of more than 30W, TSB-184-A-1 provides guidance on the separation of bundles.
The following content explained the recommendations provided in the TSB-184-A addendum on deploying 28 AWG patch cords to support power delivery.
How to Deploy 28 AWG Wire for PoE
Use Small Bundle Sizes
To maintain recommendations for temperature rise, 28 AWG cables must be grouped into small bundles. By keeping 28 AWG PoE patch cords in bundles of 12 or less, the impacts of cable temperature rise are diminished thus allowing you to stay within the suggested maximum temperature rise of 15 degrees Celsius. This assures proper heat dissipation and improves airflow around the cables.
Maintain Separation Distance
For power delivery above 30W, and to further support airflow and the opportunity for heat dissipation, all 28 AWG cable bundles ought to be separated and spaced at least 1.5 inches apart from the outer edge to the outer edge of each bundle.
Avoid Conduit/Enclosures and Overfilling
Because 28 AWG cables are only allowed in a channel as a patch cord, it’s suggested that they not be placed in conduit or other enclosures where heat build-up may occur. In addition, cable management components should not be overfilled; otherwise, heat dissipation will be suppressed and cable temperature will rise above suggested levels.
Note: There is no installation location or bundle size limitations for 28 AWG cord cables when power is not being distributed over the data network. The limitations only apply when PoE comes into play. Another thing you should bear in mind is that 28 AWG wires should never be used as horizontal, or "backbone" cabling as their maximum distance according to the standards is 10 meters;
It has been approved that 28 AWG cables can support power delivery and higher PoE levels due to their high flexibility and better airflow around server racks. Just to keep in mind that they require a focus on the installation configuration such as bundle sizes to maintain desired performance levels and safe operating conditions. Hope the above content solves your question and if you’re ready to deploy 28 AWG patch cords in your upcoming PoE projects, you can find the 28 AWG patch cords on our website FS.com.