Things to Know About Power Over Ethernet Switch

Nowadays, with the rapid development of network technology, people need a network technology that can support data transmission and power supply. The invention of power over Ethernet switches brings people a lot of conveniences because of their flexibility and reliability. Power over Ethernet switches has been applied in many applications to keep the network at peak utilisation. 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?

The power over Ethernet switch is also called the PoE switch. PoE switch belongs to a 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 a PoE switch is connected to a PoE-Capable device, it can detect automatically the same devices that you have. Each of the spare wire pairs of the PoE switch is treated as a single conductor and the electricity is injected into 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 signalling, the voltage doesn’t interfere with the data transmission.

Figure 1: How Does Power over Ethernet Switch Work?

Common Power Over Ethernet Types

According to different ports, power over Ethernet switches 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. Different types of PoE switches also have different applications.

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 switches can support data transmission and power supply. Devices connected with power over an Ethernet switch don’t need to perform power supply wiring, which can save costs and simplify the whole network management.

2. What are 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 you need to cheque 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 5e, 6,6a or 7.


It is without that power over Ethernet switches that significantly improve the efficiency of network devices. After reading the whole passage, you may likely 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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Gigabit PoE Switch vs Normal Switch

24 Port PoE Switch Power Consumption: 370W vs 740W

When purchasing a 1G PoE switch, we typically focus on the number of ports. However, power consumption is usually linked to port numbers to meet various wattage requirements. For example, a small 8-port PoE switch may offer options of 130W or 240W. A high-density 48-port PoE switch may provide up to 740W of power. Therefore, a medium-sized 24-port PoE switch with appropriate power consumption would be a viable solution for wide network applications.

Since PoE switches fail to provide sufficient power for Powered Devices (PDs) leads to low performance or random disconnections. On the other hand, for cost-effectiveness, choosing a 24-port PoE switch with an excess power budget would be a waste of money. This article will discuss PoE switch power consumption and recommend two 24-port PoE switches with different power consumption: 370W vs 740W, for your consideration.

24 Port PoE Switch Power Consumption Explanation

Total Power Consumption

The power consumption of a 24-port PoE managed switch refers to the maximum total power that the 1G PoE switch can supply to all connected PDs. In simpler terms, the total power wattage of all connected PDs must not exceed the power consumption of the 24-port PoE switch. Hence, before deciding on which power consumption PoE switch to purchase, it is essential to calculate the total power wattage of the PoE-powered devices that need to be used.

Per Port Power Consumption

Another crucial parameter of the 24-port PoE switch is the power consumption per PoE port, which is defined by either the PoE standard (IEEE802.3af) or the PoE+ standard (IEEE802.3at). A switch compliant with the PoE standard can deliver up to 15.4W of output power per port, while the PD receives 12.95W of input power due to transmission loss. Similarly, for a PoE+ switch, the corresponding figures are 30W and 25.5W, respectively.

24 port PoE switch power consumption PoE standard

Figure 1: 24 port PoE switch power consumption PoE vs PoE+ standard comparison.

24 Port PoE Switch 370W vs 740W Power Consumption Comparison

The power consumption of 370W and 740W in 24-port PoE switches caters to different levels of power wattage. Taking the S3400-24T4FP 370W and S3410-24TS-P 740W PoE switches as examples, let’s compare the scenario when fully loading these two 24-port 1G PoE switches with IP cameras. Dividing 370W and 740W by 24, we get per-port power consumption of 15.42W and 30.83W respectively. This means the 740W power consumption 24-port PoE+ switch can support 24 higher-power IP cameras compared to the 370W switch. The suggestion is: If you need to use a large number of higher-power PDs, then the 740W 24-port PoE switch would be a safer and more forward-thinking choice.

Figure 2: FS 24 port PoE switch power consumption 370W vs 740W model comparison.

24 Port PoE Switch 370W vs 740W Recommendation

Here we recommend the aforementioned advanced FS 24-port PoE switches, namely the S3400-24T4FP 370W and S3410-24TS-P 740W, for your consideration. These 24-port 1G PoE switches comply with IEEE 802.3af/at standards, allowing them to distinguish between PoE and PoE+ standards to ensure precise power delivery. Consequently, the FS 24-port PoE switch can deliver up to 30W per port, making it ideally suited for security cameras, IP phones, and wireless access points (APs).

In addition to its high power consumption PoE capability, the FS 24-port PoE managed switch boasts multiple port configurations designed to seamlessly integrate into various networks. This PoE switch consolidates 24 RJ45 auto-sensing 10/100/1000Mb PoE ports, 2 1Gb SFP ports, and 2 SFP/RJ45 combo ports into a compact 1RU form factor. The 24 PoE ports can accommodate up to 24 PDs simultaneously connected to the switch within budget constraints. Furthermore, the 2 SFP ports offer optional fibre cabling and support link aggregation of multiple switches, while the 2 SFP/RJ45 combo ports further enhance network resiliency.


Power consumption is a crucial factor to consider when selecting a cost-effective PoE switch. When deciding between a 370W and a 740W 24-port PoE switch, it’s essential to determine the rated wattage of each PD and calculate the total power budget for all devices. Ensure that the power consumption per port of the PoE switch doesn’t exceed the requirements of individual devices or the maximum power threshold of the switch itself.

If the S3400-24T4FP 370W model doesn’t meet your current needs or anticipated expansion of access points, consider upgrading to the S3410-24TS-P 740W version. Regardless of your choice, you can trust that FS.COM offers competitive prices for 24-port PoE switches in the market.

Understanding Ports of Gigabit PoE Switch

Since introducing Power over Ethernet (PoE) technology, the PoE LAN switch has become popular among wide users. However, newbies are usually confused with the multiple port configuration on the gigabit PoE switch. Since there are already regular PoE Ethernet ports for powered devices (PDs), what are the functions of other ports like console port, SFP/SFP+ port and combo port on gigabit PoE switch? This article will take 8 port PoE switch, 24 port PoE switch and 48 port PoE switch as examples to illustrate multiple ports for your reference.

Console Port on Gigabit PoE Switch

Like regular Ethernet switches, gigabit PoE switch often has one built-in serial console port, FS S3150-8T2FP 8 port PoE switch. It is the port for controlling and managing a switch since there are no display devices for a switch. Usually, the console port on a gigabit PoE switch is an RJ45 receptacle. To connect a computer directly to the 8 port PoE switch, one should use a dedicated rollover cable rather than an Ethernet cable for connection. To use the console port, you need physical access to the appliance. Therefore for terminals without serial console ports, one should attach a corresponding adaptor to the devices before cabling.

Figure 1: A display of one console port on FS S3150-8T2FP 8 port PoE switch for control.

RJ45 Port vs SFP Port on Gigabit PoE Switch

RJ45 port on gigabit PoE switch is the regular PoE port to achieve data and DC power transmission for PDs. It is an auto-sensing 10/100/1000Mb copper port supporting only Ethernet cable (Cat5e/6/6a/7) for connection. Thus RJ45 port connection is limited to 1G speed and 100m (330ft) short-distance transmission. Then how about a longer-distance transmission scenario?

Different from RJ45 port, SFP port on gigabit PoE switch has the opt of both short and long reach. Why? The mini GBIC port has inherited the compatibility of either copper or optical SFP connection. Provided you employ the corresponding SFP module and cable on power over the Ethernet switch. For long-distance transmission, you should use fibre SFP modules with fibre patch cables for optical links. For short distances, you can opt to use an RJ45 SFP module with copper network cable on a gigabit PoE RJ45 switch for electrical links. Gigabit PoE switches often provide 2 SFP ports for optical connection or uplink aggregation requirements, which enhances the network adaption resiliency of PoE-powered switches. For instance, the S3410-24TS-P 24 port PoE switch has 2xSFP ports reserved, which caters for fibre uplink to upper layer switch.

Figure 2: A display of RJ45 ports vs SFP ports on FS gigabit PoE switch.

SFP+ Port on Gigabit PoE Switch

To illustrate the SFP+ port on a PoE Ethernet switch, we’ll take the S3400-48T4SP 48 port PoE switch as an example. This 48 port PoE gigabit switch comes with 1 console port, 48xPoE+ RJ45 ports and 4xSFP+ ports. The 48xRJ45 ports are PoE-ready to power dozens of IP phones, IP cameras and wireless APs. The 4xSFP+ ports on the gigabit PoE switch serve as uplinks to connect the 10G SFP switch for uplink aggregation.

Combo Port on Gigabit PoE Switch

Though manufacturers often clearly label combo ports on gigabit PoE switches for identification, many people don’t know its function. Take the S3410-24TS-P 24 port PoE switch as an example, 4xcombo ports are reserved on this 24 port PoE managed switch. The combo port compounds RJ45 and SFP front ends in one single interface, thus it supports either copper or optical SFP link. However, you cannot use these two physical accesses on the PoE network switch simultaneously. That is, once you activate the combo SFP port on the gigabit PoE switch, you also disable the opposite copper port.


To sum up, multiple ports on gigabit PoE switches own different functionality, which enhances switching resiliency for different network cabling. RJ45 port on PoE powered switch is a normal one for a copper link to PDs. SFP port of gigabit PoE switch provides options of fibre cabling or copper cabling due to fibre SFP module and RJ45 SFP module compatibility. 10G SFP+ port on 48 port PoE switch serves as an uplink port for link aggregation in the network layer. Combo port compounds RJ45 and SFP interface in one single fabric on a gigabit PoE switch. So it helps to extend the flexibility of physical access through the network. For 8/24/48 port cheap PoE switch buying, you can find a decent offer here with optimal port configuration.