What Is PoE Splitter and How Does It Work?

Power over Ethernet (PoE) is a technology enabling power source equipment (PSE) to provide electrical power and data simultaneously to powered devices (PDs) via a network cable. PoE network brings many advantages such as flexibility, cost-saving, reliability to installations where there is no power sources near the PDs. When it comes to PoE PSE devices, PoE splitter is supposed to be on the list. This post aims at helping you to understand what PoE splitter is, how PoE splitter works, how to choose and use it, and some FAQs about it.

What Is a PoE Splitter

PoE splitters are the devices that are used together with PoE switches and PoE injectors. Instead of taking both data input and power input and turning them into a singular output, they supply power by splitting the power from the data and feeding it to a separate input that a non-PoE compliant device can use. As shown in figure 1, there are two output cables on one side of PoE splitter: one supplies data and the other supplies power. In general, PoE splitters are often used in the scenario when there are remote non-PoE devices with no nearby AC outlets.

How Does a PoE Splitter Work

There are two situations when PoE splitter is used in a network: One is the network in which PoE switch and non-PoE devices to get powered requires a connection; another is the network in which data is sent through non-PoE network switch or router connecting with PoE compliant or non-PoE compliant end devices.

As shown in the following figure, the power sourcing equipment—the PoE switch provides power source via the Ethernet cable. In this situation, the input cable of PoE splitter can connect with the switch directly. One output line supplies data and the other power. When a splitter receives a unified PoE signal, it then separates the data and power into the two different lines to the non-PoE end devices such as IP cameras and wireless access points.

If there happens to be a mixture of compatible and non-compatible PoE devices, the PoE splitter should never be connected with the non-PoE switch directly but seek the aid from a PoE injector to provide power. For example, in the figure below, a PoE splitter is connected with a PoE injector so that the power and data can be sent to the camera in the end.

How to Install a PoE Splitter

Generally, PoE splitters are needed when the devices you'd like to power such as IP cameras, VoIP phones, WiFi radios, and IP door readers are not PoE compliant. Here using PoE splitter to install a non-PoE IP camera in a network including PoE switch is taken as an example.

Installations can be easily completed in minutes. Before the installation, a PoE splitter, a PoE network switch, an IP camera, UTP cables are prepared. The PoE splitter used in this example is FS PoE splitter cable with DC 12V output.

Step 1: Connect the two output cables of FS PoE splitter to the interfaces of IP camera, one for power transfer and the other for data.

Step 2: Connect one end of UTP cable to the input interface of PoE splitter and another end of UTP cable to the Gigabit RJ45 port of the switch.

After all of this, the data and power will be transferred to the IP camera.

PoE Splitter Buying Guide

If you are stuck in choosing a PoE splitter, here is a PoE splitter buying guide to help you out.

First and foremost, you should make sure the PoE splitter you want to buy can co-work well with the powered devices in your network. Generally, the PoE splitters on the market conform to IEEE 802.3af/802.3at standards. PoE splitters can be powered by an 802.3af PoE input if the total output is less than 15.4W, or they can be powered by an 802.3at input if the total output required is less than 30W. The input voltage of powered devices should match these specifications and not exceed the output of PoE splitter. What's more, make sure the PoE standard compatibility of PoE splitter with other 802.3af/at PoE-compliant network switch or injector.

PoE Splitter FAQ

PoE splitter vs injector: What’s the difference?

Both PoE splitter and PoE injector are frequently used power device, however, they go in the opposite direction. A PoE injector, also commonly known as midspan, adds power to data that is coming from a non-PoE switch or “endspan”. It supplies power through the network cable to PoE equipment such as wireless AP. A PoE splitter also supplies power to the device however the main difference is that it splits the power from the data to a separate input that the device can use. For more information, please refer to PoE PSE Comparison: PoE Switch vs. PoE Injector vs. PoE NVR vs. PoE Media Converter.