What Is a Network Video Recorder (NVR)?

A Network Video Recorder (NVR) is a complete IP video surveillance system that uses dedicated hardware for video capture. It records video, audio, and saves it to the recording medium such as a hard drive. You can playback footage on the NVR later. You also can access live video and images from the NVR.

NVRs are seen as the successor to digital video capture cards. As NVRs offer more flexibility, such as remote management over the Internet. They come with other benefits, including better viewing and recognition of faces and license plates.

How NVR Camera Systems Work?

There are three components in an NVR camera system: a network, cameras, and NVRs. All of these parts work together to function as one system.

Network video recorder systems are newer than the traditional security camera system. The benefits of recording and storing digital data which is more convenient than an analog Digital Video Recorder system (DVR), is what makes these systems so popular.

An NVR system consists of IP cameras that encode and transfer video footage over a WiFi or wired connection to the recorder. In a wireless network, the camera still needs to be connected to a power source, and video is transferred over WiFi. The wireless camera is NOT a wired-free camera. In a wired camera system, the power and video can be transmitted over one single cable by using the PoE (Power Over Ethernet) technology.

Let’s take a look at how three components of an NVR camera system work together

NVRs: Video is received over the network in the form of data, and is stored for later review. The NVR comprises corresponding Ethernet ports which can connect to multiple IP cameras on one side.

Cameras: The camera captures the image and digitalized it before it sends it to an NVR. In general, an IP camera must connect to the NVR via either Ethernet or Wi-Fi, although wired connections give a more reliable video feed than wireless.

Network connection: If you have a wired Ethernet connection, use an Ethernet cable to connect it to the NVR. For a wireless connection, you will need to configure your settings on the IP camera. As there is no screen to input the WiFi password like on your mobile phone, the connection could become a mess, especially if you are working with a WiFi mesh network.

What Are the Types of NVRs?

Network video recorders can be generally classified by whether they have PoE ports or not.

PoE NVR: This type of NVR has a PoE switch integrated into the box. All the cameras will be attached to the PoE ports at the rear of the NVR, and the NVR can provide both power and data exchange with all the cameras at the edge. The camera needs to be PoE compatible, there is no need for a power source present at each of the IP cameras.

Non-PoE NVR: A non-PoE NVR does not have any ports for cameras to plug into on the back panel and instead requires a separate power adapter for cameras to function. However, this can be solved with an independent PoE switch to supply the power and data exchange to each of the cameras.

According to the number of channels:

The number of channels of NVRs can be divided into 4, 8, 16, or 32, 64. These channels refer to the number of supported cameras. If you are just building a basic video surveillance system, 4 or 8 channels will be enough. They are the best option for homes, retail stores, or small office applications. 16 channels are better for large buildings and factories. If you need more devices, but also need to consider budget constraints, 32 channels are recommended.

Features of NVR Systems

There are many features of NVR systems, Some of them are listed below.

  • NVR systems can record both video and audio.
  • This leads to improved image quality over CCTV cameras.
  • NVR systems provide higher image quality than traditional DVRs
  • multiple lenses IP camera lets you cover more areas with a panoramic view.
  • NVR can be wired or wireless.
  • You just need only one cable for the video, audio, and power.
  • NVR systems have the ability to identify faces, license plates, etc. due to high image quality.

Let’s answer some of the command questions below.

Will there be a video lag on an NVR camera system?

No lag should not be experienced on an IP camera system if the installation is correct. You will need to make sure that your NVR supports the cameras you want to connect, and it can handle the bandwidth and video quality. That being said, there may be some small lag in a properly designed network, but it should be minimal (0.5s or 1s). If you notice any lag after that, inspect your network for any bandwidth bottlenecks.

Does an NVR system consume more bandwidth than a DVR system?

The answer is that it doesn’t matter much, as long as the system is aware of all the recordings and saves. An NVR with a built-in PoE will have each camera connected to the back of the NVR, so the network stays unaffected. External PoE switches that are placed on a separate network will not affect the network at all.

Moreover, remember that NVR systems do not need to use the internet to save and store footage. You’ll only consume bandwidth when you connect to these systems remotely using your phone or computer——which really doesn’t matter since both systems use similar amounts of bandwidth. Additionally, these systems will only use substream mode when being accessed remotely, which has a lower bandwidth than mainstream mode.

What Cable Do I Need for a Network Video Recorder?

When it comes to wiring a PoE camera to the back of an NVR or PoE switch, Ethernet cabling is a good option. It provides power, audio, and video over one cable. Ethernet cabling comes in different standards. We recommend using CAT5e or CAT6. If you are getting the long run, it is important to choose the 100% pure copper-made cable. The CCA-type Ethernet cable causes serious power loss. The distance between the camera and PoE NVR is limited to 100 328ft (100 meters). You will need a PoE extender to extend the distance beyond 100 meters.

Can NVR Work Without Internet?

An NVR can be used without connecting it to an internet connection. However, NVRs offer features like remote viewing, and not being connected to the internet can make these features unavailable.

The recorder will still store video content, but you’ll have to watch at the site of the NVR which may defeat the point of having installed an NVR.

Active PoE vs. Passive PoE: Which Should You Use?

Power over Ethernet (PoE) is a solution that provides data transmission and electric power to devices using one cable. That means that end-users can power PoE capable devices without separate power supplies or electrical outlets near the powered device.

There are different types of PoE technology. Some PoE just provides active PoE and others provide passive. If you want to know more about the difference between active PoE and passive PoE, you can read this article.

What Is Active PoE?

Active PoE works according to a set standard specification: IEEE802.3af, IEEE802.3at, IEEE802.3bt. These are highly compatible standards. The compliant devices will complete a “power handshaking” with the PoE power supply at low power. If the power handshaking is successful, the device will negotiate the power needed and power up fully. If the handshake fails, the power supply will not deliver any power and the device will not turn on.

What Is an Active PoE Switch?

The standard/active POE switch is a PoE control chip that is built-in. It will send power to a powered device, then wait for stable transmission. If the device is disconnected, the POE switch will stop supplying power and try to detect it again.

Another similar product is the standard/active PoE injector. The PoE injector doesn’t provide switching function. It simply injects the power to the Ethernet cable and sends it together with data to the edge device. It is a handy tool to turn non-PoE switch or routers into PoE compatible equipment.

It is safe for standard PoE switch to work with non-PoE devices such as PC computers because of the power handshaking. The POE switch will only send the data without power when the non-PoE device is attached to the standard PoE switch.

What Is Passive PoE?

Passive Power Over Ethernet, or passive POE, is a type of power input to Ethernet cable that does not require power handshaking. It’s very important to understand the specifications of your device and make sure it requires the same type of POE as the input you are going to provide. For example, many CCTV cameras are passive POE but they need a 12v power supply using either a DC power balun or passive POE injector. However, there are more expensive POE cameras that have an active POE handshake and will negotiate with the switch for the correct input. The same can be said for PoE access points, which require a passive 24v power supply.

What Is Passive PoE Switch?

Non-standard/ Passive POE switches come with safety hazards. They don’t come with a POE control chip, so they can’t tell the difference between PoE cameras and other devices. This can result in transient voltages and may burn out any device connected to it. The price of non-standard PoE switches is cheaper, but you risk sending too much voltage to your devices. Please be aware that passive non-standard PoE switches deliver power without negotiation. If you aren’t sure how to install one of these, we recommend considering a standard PoE switch with active PoE control to prevent the potential hazards. All of the recommendations below are based on a standard PoE switch.

Active PoE Switch vs Passive PoE Switch: The Key Differences

Passive PoE switches deliver power over Ethernet cables, but they don’t comply with any IEEE standard. Active PoE switches, on the other hand, are compliant with IEEE standards, and there is a difference in the power supply pins of these two types of PoE switches. If safety is your top priority, you should use an active PoE switch; if you have a limited budget and cost is your main concern, a passive one might be a better choice.

Security camera systems: Active PoE Switch vs Passive PoE Switch

Active PoE: In this case, IP cameras will not turn on unless it completes a handshake between the PoE power supply and the device. If the handshake isn’t approved, then the camera won’t turn on.

Passive PoE: When using passive PoE, the camera will turn on regardless of its power parameters. Since there’s no power handshaking, you may risk burning out the camera if it’s receiving a higher voltage than it can handle.

Cost: Active PoE Switch vs Passive PoE Switch

The cost of an active PoE switch differs from the passive PoE switch mainly because the active PoE switch has a built-in power controller, which the passive one does not. This means that the passive PoE switch relies on information from outside sources to detect and classify the PD (power demand) system. As a result, it’s not surprising that the active PoE switch costs more than the passive PoE switch.

Active PoE Switch vs Passive PoE Switch: Which is the Better Choice for Your Network?

One way to keep your network safe is by using a PoE switch. We suggest active PoE switches because they can detect power wiring issues and help prevent accidents. We may also use passive PoE switches if cost is a concern, but be aware that they do not have any power detection function. It is important to make sure the passive PoE switch you buy matches the power specifications exactly to the device you are powering on, otherwise you can easily damage your device. Finally, it’s never okay to connect computers and other non-PoE devices to the passive PoE switch. Read Everything you need to know about Power over Ethernet to dive into the PoE technology.

Set up Home IP Camera System with Power over Ethernet

IP camera, also called Internet Protocol camera, is a digital video camera which captures image, compresses to video files and transmits it over network. The IP camera is widely applied in many places such as home, office building, warehouse and hotel. We will focus on setting up IP camera system at home.

More and more IP cameras are installed for safety these days. A IP camera usually put up at the front door in case of the burglary. According to a survey, about 34% burglars enter through the front door. When the valuable stuff is stolen, you may want to find out who is the murderer. If you have the suspect but no evidence to prove, no one even the police can help you. Backyard break-in can be prevented as well. So setting up a IP camera at the front door is quite essential. The backyard of house needs a IP camera. You may find something unexpected in your garden through the camera like the animal guest. Wildlife and plants can also be seen with the camera. Some cameras has night vision, enabling to monitor the garden even at night. If you have children, it is better to set a camera in the room or living room. The nanny camera is the covert camera which is hidden under the regular case such as smoke detector and PIR sensors. These cameras allow parents to monitor the activities of the children without their notices. It can avoid injuries effectively.

There are two ways to install IP camera at home, either using WiFi or wire connectivity. Be aware of the WiFi camera requires power. The power adaptor has to be presented closed to the camera to supply the DC power. The camera will be hooked up to the home WiFi network for remote viewing. One of the critical conditions is the WiFi coverage should be good enough at the installation spot. The camera takes significant bandwidth to stream the real time video online. The walls are always the obstacles which may block the WiFi signal. There are many ways to improve the WiFi if it is too bad in the field.

The second solution is to use wire IP camera system with power over Ethernet (PoE) technology. The PoE allows single Ethernet cable to transport data and power to the remote IP camera. The AC outlet is eliminated in each cameras. A home IP camera system can be done by yourself with Cat 5e or Cat 6 cable when PoE is employed. Moreover, the wire connection has better connectivity than WiFi. The PoE installation is plug and play. Just connecting the cameras to PoE products like PoE switch or PoE NVR with standard Ethernet cables, your camera system gets ready to work. The PoE technology needs no certificated electrician, so the cost is lower.

Several connection ways can be chosen to set up the IP cameras system. First way is to use PoE switch. It is the most direct and easiest way to power IP cameras. The cameras are connected to the RJ45 ports of the switch by using the Cat 5e/Cat 6 ethernet cable. If the camera is set up outdoors, the cable should be protected with plastic tube.

PoE NVR is the second choice. PoE NVR can be considered as a video recorder with PoE switch integrated. It simplifies the installation. All the cables will be wired back to the rear connection of PoE NVR.

If the network infrastructure is existed without PoE, a PoE injector can be added on to convert non-PoE products to PoE-supported. PoE injector and PoE spitter are two kind of devices to convert the PoE network.

The setup of home IP camera system becomes simple and easy with PoE technology. Find out the differences between PoE NVR and external PoE switch for IP camera system.

What is PoE IP Camera?

Before moving to the PoE IP camera, let’s make clear what is IP camera first. IP camera, also referred to Internet Protocol camera, is a digital video camera which captures image and transmits it over the network. IP camera needs power and communicating network to function.Therefore it has to be used with Ethernet cable to send data and the power to supply the camera. PoE IP camera has integrated with Power over Ethernet technology. Both data and power are transported through single Ethernet cable(Cat 5e/Cat 6) and videos are transmitted in the same cable. The PoE IP camera simplifies the cabling job and gets rid of the power adaptor closed to each cameras.

There are many ways to power a PoE IP camera. We will go through each of them below.

PoE IP camera can be connected and powered by PoE NVR. PoE NVR, or name PoE network video recorder, is little different from the traditional NVR. PoE switch is built in the video recorder, which can provide power and data to the cameras. Cat 5 or Cat 6 ethernet cable is the standard network cable to transmit data and supply power in PoE. To link PoE IP camera to PoE NVR, only one Ethernet cable is needed. Simplified installation reduces time and cost. PoE NVR can record video files and export it as forensic footage. It isolates IP video camera system from the main network. Usually PoE NVR has four or eight Ethernet ports. If you want to set up few IP cameras in the system, PoE NVR is a good choice.

PoE switch can also power PoE IP camera. The PoE switch connect to the cameras for power supplying and data exchanging. Using PoE switch can link multiple IP cameras and the network video recorder all together. You can choose the number of ports of PoE switch based on the system design. There are 8/16/24/48 ports PoE switch available in the market. This solution is made for those who want to set up PoE IP cameras for small-medium system.

The third way to power the PoE IP camera is by connecting to a PoE injector. The injector can add the power to Ethernet cable and the power is transported to remote IP camera as well as data. Power is taken from AC outlet before converting to DC48V. Usually the injector has two RJ45 ports. The data port will be linked to network hub to receive the data. PoE port will be connected IP camera for transporting the power and data. Since there is only one PoE port, single injector can power one PoE IP camera with this solution.

The PoE injector is able to work with PoE IP camera. If the camera doesn’t support PoE, a PoE splitter can be added to convert non-PoE IP camera to PoE available. The PoE injector and splitter usually work in pair. PoE splitter receives both data and power from the injector, and then separates them into two different outputs to the IP camera.

Last way to power PoE IP camera is to use passive PoE injector. The passive injector doesn’t have any protection for the power transporting. The users should possess the basic know-how to operate passive PoE splitter. The passive PoE injector simply forwards power from the external power adapter to remote IP cameras. It can only power up low voltage device. The passive PoE injector is the primitive PoE solution which works in a short distance.

The cable distance is limited to 100 meters in PoE system. Using PoE extender can extend the network beyond 100 meters.

Different Types of Power over Ethernet Adaptor

PoE adaptor (also name PoE injector) is a product which can send power and data through single Cat 5e/Cat 6 to remote powered devices. The PoE adaptor provides power solution to a wide range of network equipments such as IP cameras, access point and VoIP phone. Due to transparency to TCP/IP protocols, no configuration is required. The PoE adapter is a plug and play product.

PoE adaptor has different types based on power voltage. There are 12V/24V/48V adaptor. 12V PoE adaptor is the most primitive adaptor. As we know, an Ethernet cable has four twisted pairs. Two of the pairs are used for data delivery, and the spare pairs sent power to remote devices. No protection protocol is used in this type of adaptor. When the 12V adaptor is powered, electricity will be sent directly to PoE devices. Usually there is passive splitter at the other end to separate the power for remote device. As the voltage will drop down sharply while the distance is increasing, the 12V PoE adaptor can only be used in the short distance transportation.

Another type of PoE adaptor, 24V adaptor, can supply more power to devices. The DC24V injects the power to the Ethernet cable and the DC12V regulator is required at the remote device in order to output correct voltage. 24V adaptor sends power to 50 meter far. Voltage drop is being taken care of by the voltage regulator.

The last type of PoE adaptor is 48V adaptor. Before introducing the 48V PoE adaptor, one point should be known. That is passive and active PoE adaptor. Non-standard adaptor has no built-in PD signature detection. The adaptor will release DC48V directly when the powered device is plugged in at the end of RJ45 connector. The standard PoE adaptor will verify the remote device before adding the power to the Ethernet cable. The PD signature guarantees the safe process for power over Ethernet solution. Signature detection can avoid the device burned out and protect from the power surge. If the powered device fails to be verified as standard PoE devices, the adaptor will stop the power.

12V PoE adaptor can be used in 12V IP access point and other low voltage devices in short distance. A passive splitter is needed to split the power from the data. As no protection is added, you must have basic knowledge about how to operate the passive PoE adaptor. If you mix up with the twisted pairs, the remote device will be damaged immediately. The 24V PoE adaptor usually works with specific products. The regulator has to be included inside to convert to DC12V. It is better to limit the distance to 50 meters because of the voltage drop. The standard 48V PoE adaptor complies with the IEEE 802.3 specification. As long as the powered device also meet IEEE802.3 standard, the solution is plug and play. The adaptor can deliver data and power up to 100 meters.

To learn more about PoE adaptor or injector, check how to choose the right PoE injector for your network.

How to Choose a PoE switch – Actual Power Budget

The PoE switch sends not only the data, but also the power to the remote IP device, so the AC outlet closed to devices can be eliminated in the field. As we all known, the electric equipments only take the power it consumes. It has no relationship with the power budget from the power source. For example, the access point only draws 5W even 100W power adapter is being used. The below is power reference consumption of convenient network device.

Access point – 5W
IP camera without infrared – 6W
IP camera with infrared – 15W
Infrared PTZ camera – 20W
Infrared camera with heater -50W
Access control with door lock strike – 60W
Point of sales (POS) – 65W

These are the general estimated power. You may find the accurate data of your device from the label.

How to pick the PoE switch to meet the power demanding? There is IEEE 802.3 standard you can refer to. The typical two are IEEE 802.3af (also name PoE) and IEEE802.3at (also name PoE+). The PoE output 15.4W and the PoE+ output 30W. However this is not the actual power budget. It is only the maximum power that PoE switch injects to the Ethernet cable. The remained power budget is 12W for PoE and 25.5W for PoE+. Why there is difference between the output from PoE switch? That is because it always has power loss inline when the power is transported on the conduct. Then the power loss is converted to the heat eventually. The new IEEE 802.3bt standard is ready now. This new standard is capable of injecting 95W high power and the remained budget is kept to 72W at the front devices. It is going to benefit the application such as access control, POS, interactive display, cellular base stations, etc.

Can we have larger power budget if the distance is totally shorter than 100 meter, like only 50 meters? The answer is negative. The power budget has been predefined in IEEE 802.3 specification. The remained power is set to 72W even the distance is 1 meter. There are IC on both PoE switch and powered devices to control the power budget. However the low quality Ethernet cable could compromise the remain power. If the power loss is larger than it expects, it will create seriously voltage drop which could make the powered device(PD) fail to start up.

Do I actually have 30W on each ports if the PoE switch support PoE+? That may not be true. The PoE switch uses the shared power source. You may read the specification – 16 port PoE+ switch with 180W power. If all 16 ports supply 30W, it should be 480W power budget in total. As the electrical device only will take the power it consumes, some of the devices may only need 5W, like the access point. The 180W still could be enough for the whole system. It doesn’t have to be 480W for 16 ports outputting 30W.

Except for considering the maximum output of each ports, the total power demanding of the whole system needs to be calculated while choosing PoE switch. The IEEE 802.3 af/at/bt predefine the power capacity of single port. The real output also depends on the total power budget in the PoE switch.

There is one more thing about the power budget. It is better to reserve margin when you design the system. If the devices needs 12W, choosing PoE+ switch(FC 16 port switch) which can supply 25.5W is better because the system will not fully load all the time. The maximum cable distance is 100 meters between the PoE switch and powered device. Click choose the PoE extender can extend the network beyond 100 meters to learn about information.

Long Distance IP Camera Setup with PoE Network Extender

If you plan to install IP camera over 100 meters far away from the monitoring center and worry about the distance, PoE network extender can help. The network communicating will start getting worse when Ethernet cable is beyond 100 meters. Some unexpected phenomenon like connection drop and high latency will appear. The PoE network extender is designed to resolve these issues. Rather than convenient network extender, the Power over Ethernet technology is integrated to PoE extender which allows power and data are transported through single Ethernet cable. The power will be sent from the center as well as the data pass through each extender. 4 PoE extenders together can extend 500 meters PoE network by using daisy chain setup.

A PoE switch or PoE injector is required in monitoring center to inject the power to the Ethernet cable. So no extra power source is needed for each extender. The AC outlet is eliminated. The setup process is simple – plug and play. One end of PoE extender connects the cable from the PoE switch, and the other end links to extended cable.

Somethings need to be addressed out while using PoE extender to work with IP camera.

Usually the cable can be hanged in the air or buried under the ground. If you choose to hang up the cable, it is better to add plastic tube to protect the cable. The PoE extender is waterproof and requires no extra protection, but the cable may need the protection from harsh environments outdoors. Adding the tube also can ease the electricity discharge. When power and data are being transported in long distance, it becomes more easier to absorb the ESD in the air which can be sent to the devices and damage them eventually. If cable line is buried under the ground, the PoE network extender need to be placed in some protective closure because of moisture in the soil. Placing the extender in a closure is good for future maintaining.

High quality cable should be used when setting up IP camera. Cat 5e/Cat 6 are qualified grade. Make sure pure copper cable is used. Cat 5e/Cat 6 has high speed, but it doesn’t guarantee the material of the cable. The pure copper can decrease the power loss on the cable, otherwise power loss will turn to new issues if low quality cable is used. It will be converted to heat inline and create voltage drop at the other end of the cable.

What will happen while doing the wrong connection? If the IP camera cannot be powered, first thing is to check the PoE extender. The extender has two different ports, out and in. In port should be linked to PoE switch or injector to receive power and data and out port is to power IP camera. The IP camera could not work if the extender’s port is misconnected. The next thing is to make sure the twisted pair has the right sequence. Move the IP camera to the connection before the first extender. This can help you role out the issue even you don’t have network tester. The connector always needs to be paid attention. As more connectors are created, the possible failed points increase as well. The final thing is to be sure the pure copper cable is employed in the system. As we mentioned above, low quality cable can create power loss and voltage drop. If the remained voltage is lower than the camera required, the PoE power system will never turn on.

Want to find more information about extending the network without the limitation of distance? Click best way to extend the network beyond 100m.

How PoE Injector Works with Splitter for Power over Ethernet?

When building a network system, PoE technology is always good to be considered. PoE (Power over Ethernet) makes power supply and data exchange via one Ethernet cable possible. PoE injector and splitter are two major equipments for transporting the power and data over single ethernet cable. The injector adds the electricity power to Ethernet cable, and the splitter separates the power from the data at the other end. Injector usually has two RJ45 ports, one for receiving data from switch and another for sending out power/data combined signal to the remote devices. Similar as injector, the splitter also has two RJ45 ports. Instead of sending out power and data, the splitter receives data and power and then separates them for non-PoE device.

PoE injector and PoE splitter usually work in pairs. The injector sends out power and data to splitter, and PoE splitter separates data and power into two different cables to make devices work. The PoE injector and splitter solution is designed for non-PoE devices or a mixture of PoE compatible and non-PoE compatible devices.

Except for PoE injector and splitter, a non-PoE switch is required in a typical network system. A non-PoE switch provides platform for connected devices to exchange data. As the PoE injector doesn’t process the data, it has to be connected to a non-PoE switch for data exchange. The PoE injector usually has AC input so it should be plugged in AC power outlet. Now the injector can take the power from outlet and combine it with the data from non-PoE switch before sending out. The splitter stays at the other end of the cable closed to powered device (PD) such as IP camera, access point, VoIP. These powered devices receive the power and data separately from a splitter.

There are three IEEE 802.3 standards for PoE technology. As long as PoE injector and splitter comply with IEEE802.3 standard, it guarantees the power transporting with pre-defined power budget in the system safely.

Different standard provides different power budget. IEEE 802.3at, 802.3af and 802.3bt standard are commonly used. IEEE 802.3af supplies 15.4W, which is the lowest among the three standards. 30.8W power can be provided when the injector and splitter are compatible with IEEE 802.3at (also named PoE+). The IEEE 802.3bt standard is the next generation PoE which increases maximum PoE power up to 95W by taking all 4 twisted pairs wires to transporting the power.

Voltage is another factor in the PoE injector/splitter power system. DC12V and 5V are two main types of power voltage being used in the market. A lot of PoE splitter are designed for DC12V power output. If you use low voltage device like IP camera, 12V PoE splitter is the right one.

Both Cat 5e/Cat 6 ethernet cable can be used to setup PoE injector/splitter power system. Cat 5e/Cat 6 consists of four twisted pairs of wires. Two of the twisted pairs are used for data sending in fast network, which is also called data pair. The spare pairs could be employed to transport the power. Pure copper Ethernet cable should be chosen because pure copper can reduce the power loss on the cable. The electricity transporting on conducts will generate energy loss and be converted to heat. If the low quality cable is picked, the power loss will become serious.

Using PoE injector and splitter solution simplifies network system setup. The AC outlet is removed at the front end and the power is sent by the injector from the center. It is cost-effective and money-saving. Attention should be paid when choosing the PoE injector and splitter.

Power over Ethernet voltage 12V-24V-48V-57V

The power over Ethernet inject the power to cat5e or cat6 network cable, so the remote ip devices is able to retrieve both power and data from single cable at the other end. According to the standard EN62368 (for AV & IT Equipment), the limit at which under no safeguards are required is DC60V or 2mA. We are seeing different voltage not higher than or equal to DC57V are being used on power over Ethernet. Let’s talk about the differences about these voltage on power over Ethernet.

One thing need to be addressed before we move ahead is the voltage drop. While using cable to send the power, there is always power loss inline cable which will be converted to the heat. The consequently result is the voltage drop at the other end. If the voltage drop down lower than the remote devices require, the whole system will stop working. For example, the WiFi router requires DC9V, but the remain voltage is only 7V after 100 meters transporting, the power will not be able to supply the WiFi router.

DC12 voltage power

This is the raw solution. The power is injected to the spare pairs of the Ethernet cable and being sent to the remote network devices. There is no process and protection for the power. This is the most simplest PoE solution which could still work for short distance and low power consumption on indoor application. If use this solution to transport power longer than 20 meters, the remain voltage will drop down sharply at the other end.

DC24 voltage power

It is popular in some telecom application. Some of electrical devices require DC12V input. Injecting DC24V to the cable can adapt to the voltage drop after medium distance transportation such as 50 meters. The other side usually requires voltage regulator to convert remain voltage to DC12V. There is around 12V margin to adapt to the voltage drop, that is why the maximum distance could be longer.

DC48 volts power

DC48V is the specification from IEEE802.3 PoE standard. According to IEEE802.3, the power is capable of transporting up to 100meters as well as data. The other end requires regulator to convert to lower DC output such as 12V or 5V. IEEE802.3 also specified the power budget within 100meters including PoE PoE+, PoE bt. The higher power consumption, the higher the current inline, so the sharper voltage drop will be. As long as the products are IEEE 802.3 compatible, the voltage is no need to be concerned. Both issues has been considered when the standard was developed. Not only IEEE802.3 standard PoE use DC48V. Some of the passive PoE also use DC48V.

Over DC48 voltage

In these years the higher voltage such as DC55 has been applied to power over Ethernet including IEEE 802.3 compatible products. The benefits of high voltage PoE is reducing the power loss cable inline and relase the voltage drop issue. For example the IEEE 802.3bt PoE power system can transport 95w power over single Ethernet. If use DC48V, the voltage drap becomes seriously when the power is being full load. The DC53V is taken in, so the remain voltage is still enough after 100 meters transporting.

IEEE 802.3 PoE is considered as safe power system. That is because not only the power voltage has been designed for Ethernet cable, but also PD signature is introduced in the standard to guarantee the power PD signature is being sent to the device.

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