The Future of PoE, Safety Risks and How to Mitigate Them

Future of POE

Power over Ethernet (PoE) is a useful standard that provides efficient delivery of power and data along a single medium. It helps cut down on capital expenditures as well as installation costs while improving overall reliability. With PoE it’s possible to provide data and power with a single twisted pair cable (Cat 5e, 6 or 6a) making everything easier to maintain.

In some areas of your network, PoE is as standard as cabling itself while in others it has not gained traction. Currently, PoE powers more than 100 million devices such as wireless access points (APs) and Internet protocol (IP) phones. The limitation has been that current PoE standard only support up to 30W of power to devices which limit its application.

The good news — this limit is about to change. This year, we’re expecting an update to the standard that will help increase power up to 100 watts.

Types of PoE

Before we talk about what’s coming, let’s review the current types of PoE. In the table below you can see that we have PoE (Type 1) and PoE+ (Type 2) which go up to 15.4W and 30W respectively.

These circuits are delivered using a standard data communications cable and use two pairs of wire do so. Due to the low wattage, any data cable starting with Cat 5e will give you a maximum speed of 1Gbps within the 100m distance allotted by TIA standards for delivering ethernet connectivity without having to worry about heat.

For this reason, PoE has been a workhorse across the LAN, the data center and some outdoor applications for the past 15 years.

As with all standards, market needs have surpassed the current standard. Users want to power devices such as high powered pan/tilt/zoom cameras, TVs, lighting and building management systems among others. For this reason, IEEE has been working on the PoE ++ and 4PPoE additions to the standard.

As you can see in the table below, the changes will do more than just deliver more power. We expect to see PoE++ (Type 3) and 4PPoE (Type 4) to achieve 60W and 100W of power respectively while providing 10 Gbps of data across four-pair category cables.

This is excellent news for an industry that is clamoring for more data and power. Of course, there are always challenges when working with new technology, and in this case, it comes in the form of heat.

Fortunately, a new UL standard and an updated National Electrical Code (NEC) will help users safely deploy more power across their network. Just be prepared that your current cabling infrastructure may not support delivering more than 60W of power.

Check out the chart below for another look:

Type
Standards
Maximum Current
Number of
Energized
Pairs
Power at Source
Power at Device
Maximum Data Rate
Standard Ratified
PoE
IEEE 802.3af (802.3at Type 1)
350 mA
2
15.4 W
13 W
1000BASE-T
2003
PoE+
IEEE 802.3at Type 2
600 mA
2
30 W
25.5 W
1000BASE-T
2009
PoE++ 
(4PPoE)
Proposed IEEE 802.3bt Type 3 
Proposed IEEE 802.3bt Type 4
600 mA  
960 mA
4
60 W 
100 W
51 W 
71 W
10GBase-T
Expected
1Q2018

The NEC and the UL LP designation

The new PoE standard for 2018 is starting to get people excited. More power equals more devices, but it also means more heat, and that is where the NEC and UL come in.

The 2017 NEC covers the next generation of PoE applications. However, the code only addresses systems with power levels above 60W which only applies to 4PPoE. It prescribes the maximum number of cables allowed in a bundle based on tables found within the document.

You will also see that many states and localities have not adopted the latest document, so it will take some work to determine what steps should be taken to ensure compliance with local codes as well as providing a safe environment once the infrastructure is operational.

This is where the UL listing comes in to play. They have done the legwork for everyone to help provide peace of mind when installing higher powered solutions. Per the UL website, their LP cable designation indicates that the cable has been evaluated to carry the marked current under reasonable worst-case installation scenarios without exceeding the temperature rating of the cable.

The certification takes into account significant bundle sizes, high ambient temperatures and other issues related to environmental effects, such as enclosed spaces or conduits. This allows an end user to install a cable in 2018 without having to worry if their infrastructure can handle higher powered needs in the future.

Whether you choose a LP rated cabling or use the 2017 NEC ampacity table guidelines (725.144) and inspections, you will be able to deploy the new standards without heat concerns.

Ampacities in 4-Pair Class 2 or Class 3 Data Cables chart

PoE is Here to Stay

PoE has been a pillar of commercial network infrastructure since 2003 and is continuing to adapt to new applications and standards as they develop. The ability to send power and data over one cable without compromising the quality of either is a significant benefit to contractors, building managers, and the end user.

Contact your local Graybar representative to find out how we can help you with your data and power needs.