Things to Know About Power Over Ethernet Switch

Nowadays, with the rapid development of network technology, people are in need of a network technology that can support data transmission and power supply. The invention of power over Ethernet switch brings people a lot of conveniences because of their flexibility and reliability. And power over Ethernet switches have been applied in many applications in order to keep network at peak utilization. So what is power over Ethernet switch and how does it work? This post will give you the answer.

What Is Power Over Ethernet Switch and How Does It Work?

Power over Ethernet switch is also called PoE switch. PoE switch belongs to network switch or hub, it can not only transmit network data, but also supply power to connected devices over one Ethernet cable at the same time, which can greatly simplify the cabling process and cut costs. At the same time, PoE technology is applied in different devices, such as IP cameras, IP access points and voice over IP (VoIP) phones.

When PoE switch is connected with a PoE-Capable device, it can detect automatically the same devices that you have. Each of the spare wire pairs of PoE switch is treated as a single conductor and the electricity is injected onto the cable. And PoE switch can sometimes be transmitted on the data wires by applying a common-mode voltage to each pair. Because the twisted pair Ethernet cable uses differential signaling, the voltage doesn’t interfere with the data transmission.

PoE switch, power over Ethernet switch

Figure 1: How Does Power over Ethernet Switch Work?

Common Power Over Ethernet Types

According to different ports, power over Ethernet switch can be grouped into three common types, they are 8-port ,24-port and 48-port power over Ethernet switches. Different types differ in switching capacity, price and other aspects. For example, different PoE switches have different switching capacities and prices in FS (Figure 2). Different types of PoE switches also have different applications.

POE switch, power over Ethernet switch

Figure 2: Comparison of Different PoE Switch in FS

Confusing Questions About Power Over Ethernet Switch

1.What are the differences between PoE switches and normal switches?

They differ in reliability, function, cost and manipulation. Compared with normal switches which only support data transmission, power over Ethernet switch can support data transmission and power supply. Devices connected with power over Ethernet switch don’t need to perform power supply wiring, which can save costs and simplify the whole network management.

2.What is the differences between PoE and PoE+?

Firstly, one difference between PoE and PoE+ is the actual Institute of Electrical and Electronics Engineers (IEEE) standards themselves. PoE is 802.3af, while PoE+ is 802.3at. The maximum capacity of PoE can reach 25.5 w, while the maximum capacity of PoE+ can reach 35.4 w. Secondly, the maximum support current of PoE is 350mA, while PoE+ is 600mA.

3.Can I use PoE ports for non PoE devices?

Yes, you can. All PoE switches have auto-sensing PoE ports, which means that the PoE port will detect if the connected device is a PoE device or not. But it is very important for you to check whether your PoE device supports 802.3af or 802.3at. Because non-standard PoE switches don’t have auto-sensing PoE ports, which is more likely to damage the network port.

4.Do all Ethernet cables support  PoE?

Yes, nearly all Ethernet cables support PoE. PoE will work with existing cable, including Category 3, 5, 5e or 6.


It is without that power over Ethernet switches significantly improve the efficiency of network devices. After reading the whole passage, you may likely to have a general idea of PoE switches. FS provides different types of PoE switches for Ethernet PoE power supply and data communication. For more information, just reach us via

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