Are you looking for a solution to easily power your IP cameras? You just got to the right place. You will learn how a PoE Switch can solve your problem.
==> PoE stands for Power Over Ethernet, it is a technology to power devices such as IP phones, routers and IP cameras over network cables.
You just need to understand how PoE works and how devices such as PoE switches and PoE Injectors (Midspan) can help you with your IP CCTV projects. That's what you will learn in this article. So just keep reading...
What is PoE (Power Over Ethernet)?
OK, when you search por PoE on Internet, sometimes you get results about the book writer, Alan Poe. He is really a good writer, but I will talk about something else here. I want you understand about Power Over Ethernet.
In 2003 the Electrical and Electronics Engineers group, also known as IEEE developed the standard called IEEE 802.3af that provides up to 15.4W over network cable (UTP cable). In 2009 the standard 802.3at was created to provide up to 25.5W over network cable.
Power sourcing equipment
Power sourcing equipment (PSE) is a device such a network switch or PoE injector (aka midspan) that can provide power over the network cables.
Powered device (PD) is a device such as IP Phone, IP camera or router that consumes the power generated and sent by a PSE.
Since it's not longer necessary to run a separate power cable to the IP cameras, CCTV installation became much easier and inexpensive.
What are the benefits of PoE?
As a industry standard, this technology have been used for many years in all type of IP projects. See below the list of its benefits:
PoE can save you time and money
Since running extra cable to power devices is no longer necessary, it's possible to save money by cutting investments on expensive power cables, outlets and all the infrastructure equipment related to electric installation.
PoE has simplified network installation while improving energy efficiency and reducing specialized technical labor costs with electricians.
In some large IP camera installation, the savings with infrastructure are estimated to up to 50%
PoE make the installation simple
Running only one network cable from a PoE switch to a device such as an IP camera is much simpler than run extra cable just to power the device.
PoE allow better power management
A a PoE switch can be installed in a central location and power all the devices at once, it's also possible to monitor how much power each device is using by simply looking at the switch PoE management interface.
PoE types and standards
Before power up IP device, is necessary to check the total power required to make it run properly. After you find out that information you can use the correct type of switch or power injector that will meet your needs.
See below the standard based on power that can be used by the devices:
Type 1: IEEE 802.3af
Type 2: IEEE 802.3at
Power available at powered device
Maximum power delivered
Voltage range at powered source
Voltage range at powered device
Maximum cable resistance
So, when you buy an IP camera, just check the datasheet or manual to make sure its specification complies with the *IEEE 802.3af or 802.3at standard.
OK, it's time to learn more about PoE switches for IP cameras. There a lot of different options in the market and you need to understand which one is better for your IP CCTV project.
Old IP camera projects use two cables to send power and data to the camera, while modern IP camera projects uses only cable to send data en power.
A PoE switch is very useful for IP CCTV project, because it allows easy power management from a central location such as a surveillance room.
PoE switch for small projects
Small projects require simple solution and the use of good quality network PoE switch can make everything simple, inexpensive and easy to manage.
Please don't try to save money by purchasing unknown brand PoE switches, just because they are a little bit cheaper that a well-known brand device.
Some well-known good brands are: Cisco, HP, Dell, Netgear
PoE Injector (Midspan)
A power injector is a device that can be installed between a regular network switch and a device that will be powered, such an the IP camera.
For projects that already have the network infrastructure in place, sometimes is too expensive to replace all the regular network switches and for that case, it's possible to use power injectors as shown in the picture below:
Example of project using PoE switch
Let's see an example of a IP camera project that uses PoE switches.
Suppose there's a project to install 24 IP cameras and you want to power all of them by using a PoE switch. The first thing you need to consider is how much power each camera will consume and multiple by 24.
The picture below shows the IP camera information. Note that the camera consumes a maximum of 12W when using PoE Class 3.
So, doing the math: 24 x 12W equals 288W. That's the total power necessary for all the IP cameras that will be installed
The PoE switch catalog informs that IEEE 802.3af is supported on all ports.
As long as the switch total PoE power is equal or higher than 288W, that will enough for the project. So you must check that information with the dealer before buy the PoE switch.
The myths about Power Over Ethernet
I can't mix PoE and non-PoE devices in my network
Yes, you can, A PoE switch will send power to the devices that need to be powered and the non-PoE devices will not receive any power, so obviously it's necessary to have a separated power supply to power them.
PoE requires special wiring
No way. It's not necessary to run any type of special network cable.
Regular network cables from Cat5 to cat7A either shield (STP) or Unshielded (UTP) are suitable to be used for the installation.
All PoE devices are the same
No, they are not. Sometime you have a power supply for some device such as a wireless transmitter antenna and it's written there "Power Over Ethernet", but it could be using a different standard that's not compliant with 802.3af/t.
So, make sure you are using compliant devices before power them up.
PoE devices are expensive
Wrong again. Switches, and midspan that are 802.3af or 802.3at compliant are inexpensive devices that are manufactured globally in a large scale.
Example 1: Using a PoE switch
See below an example of a 16-port Netgear Switch on Amazon. That's a Smart model that has some interesting features such as VLAN
NETGEAR 16-Port Gigabit Smart Managed Plus Switch (JGS516PE)
Example 2: Using a Power supply + switch
The cost of a CCTV power supply plus a regular switch is almost the same of a PoE switch, however if you consider the extra costs with cable, accessories, infrastructure and labor, the price of this solution will much higher.
InstallerCCTV 18 Output 29 Amp 12V DC CCTV Distributed Power Supply Box for Security Camera
NETGEAR 16-Port Gigabit Ethernet Unmanaged Switch (GS316)
There's also the fact switch smart features will not be available.
Consider to use PoE switches in your IP CCTV project to reduce the costs and headaches with extra power supply and extra labor. If necessary you can use midspan as an alternative solution.
Want to learn more ?
If you want to become a professional CCTV installer or designer, take a look at the material available in the blog. Just click the links below:
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Claudemir Martins is a former Samsung Engineer with 19+ years of experience in the surveillance industry. He has been traveling around 17 different countries to teach people how to design, and install CCTV systems. He is currently working for Axis Communications as a Technical Services Engineer and living in the United States with his family.