Power over Ethernet (PoE) technology allows a single Ethernet cable to carry both data and electrical power to compatible devices. It simplifies network installations by reducing the need for separate power adapters and electrical outlets. However, not all PoE standards deliver the same amount of power.

Understanding the differences between PoE, PoE+, and PoE++ helps you choose the right network switch, Ethernet cable, and power solution for your installation.

What Is the Difference Between PoE, PoE+, and PoE++?

The main difference is the amount of power each standard can deliver. All three technologies support network data transmission, but higher-power standards can operate more demanding devices.

Power figures represent the standard’s maximum rated power levels, not guaranteed consumption or output in every installation.

1. PoE (IEEE 802.3af)

Standard PoE delivers up to 15.4 watts from the power-sourcing equipment, with up to 12.95 watts available to the powered device after cable losses.

It is suitable for low-power networking equipment, including many VoIP phones, basic IP cameras, and simple wireless access points.

PoE is often a practical option for small offices and basic security systems where connected devices have modest power requirements.

2. PoE+ (IEEE 802.3at)

PoE+ increases the maximum power supplied by the source to 30 watts, allowing up to 25.5 watts at the powered device.

This additional capacity supports more demanding equipment, such as advanced wireless access points, certain PTZ cameras, and video phones with larger displays.

For businesses upgrading their wireless networks or security systems, PoE+ can provide a useful balance between power capacity and installation cost.

3. PoE++ (IEEE 802.3bt)

PoE++, based on IEEE 802.3bt, supports higher-power devices through two power classes commonly referred to as Type 3 and Type 4.

• Type 3: Up to 60 watts at the source and 51 watts at the device.
• Type 4: Up to 90 watts at the source and 71.3 watts at the device.

These standards are useful for high-performance wireless access points, advanced PTZ cameras, multi-radio networking equipment, and certain other devices with greater power demands.

Before choosing PoE++, verify the device’s actual power requirements and confirm that the switch supports the required standard and power level.

Which Ethernet Cable Is Best for PoE?

Cat5e and Cat6 cables can both support PoE when they meet the relevant requirements. Cat6A is another option for installations requiring higher data bandwidth or additional performance headroom.

For PoE installations, genuine copper conductors are strongly recommended. Copper-clad aluminum (CCA) cables have higher electrical resistance than pure copper and can cause greater voltage drop and heating, particularly under higher power loads.

Cable length, conductor size, connector quality, installation conditions, and the total switch power budget also affect performance and reliability.

How Far Can PoE Run?

A standard Ethernet channel generally supports a maximum distance of 100 meters (328 feet), including permanent cabling and patch cords. PoE installations typically follow this limit, although actual performance depends on the cable, connected devices, and power requirements.

For longer distances, suitable PoE extenders, additional switches, or fiber-optic links with separate power solutions may be required.

How to Choose the Right PoE Standard

Choose PoE for compatible low-power devices, PoE+ for equipment requiring moderate power, and PoE++ when a device needs a higher power level.

Always check the device specifications, Ethernet cable quality, switch port capabilities, and total available power budget before purchasing equipment.

Ultimately, selecting the correct PoE standard helps deliver reliable connectivity, simplifies installation, and ensures that your network devices receive the power they need to operate properly.