Until a few years ago, the power source of security cameras was still limited to AC power, but with the advent of technologies, installers are now using Power over Ethernet (PoE) as a standard method to power IP cameras of all sizes and shapes from a single access point, provided that PoE provides a budget-friendly way to deliver power and data to the powered devices (PDs) in locations where AC power is expensive, inconvenient and infeasible to install. Depending on the models and specifications, the rated power consumption of most IP cameras could vary from 4 to 15 watts, but with the influx of new designs, there presents a new challenge with the introduction of the PTZ camera, a digital video camera that requires more power than that is capable of the legacy PoE standards (i.e. PoE or PoE+).
The PTZ cameras built with special features like IR night vision and pan-tilt-zoom normally consume more energy to operate at their full throughput. 40W is average for running a PTZ camera that comes with built-in motors, stabilizers, IR illuminators, etc., but considering the power loss over the long cable run, at least 50 watts of power needs to be available at the PSE. And in some old-fashioned models that specify a required power of 30W for camera operation only, a separate power source (low-voltage 12/24V AC) is usually required to power the external heater or blower of the PTZ camera to make it function properly in extreme environments. And this brings the value of PoE power into question: is it restricted to powering the camera only? And even for models that rely on PoE for both camera and heater functions, they could fail at the most inopportune time due to power insufficiency. Thus, to give the full play of PTZ cameras in the video surveillance system, a higher power supply is needed, and here’s where the latest PoE standard IEEE802.3bt (PoE++) comes in.
PoE Before IEEE802.3bt
The IEEE802.3 standards were first initiated in 2003 to govern the delivery of power over Ethernet cables and regulate the cooperation between different network devices. Before the introduction of IEEE802.3bt in 2018, there were only two PoE standards: IEEE802.3af (Type 1) and IEEE802.3at (Type 2). The Ethernet cable consists of 4 twisted pairs and these pairs often correspond to 8 pins. Different PoE devices often use different pinout pairs for power transmission. Type 1 and Type 2 use two sets of twisted pairs for data transmission and save the other two for power delivery. The former supports Cat3 cables or better, while the latter will need at least Cat5 cables for proper operation.
IEEE802.3af (PoE) was the first PoE standard used for IP cameras, specifying a total power supply of 15.4W over 100 meters of cabling, ideal for installing low-voltage appliances like VoIP phones and fixed cameras. For devices that require higher levels of PoE, IEEE802.3at (PoE+) was released in 2009 which can source 30 watts of power to the PD, capable of supplying power to both PoE and PoE+ PDs like WAPs, LCD displays, security alarms, etc. Every PoE/PoE+ device will be assigned to a PoE Class depending on how much power it consumes so as to improve the management of the PSE’s power budget. The PoE classes range from 0 to 8: PoE defines Classes 0-3, covering the input power at the PD from 3.84W to 12.95W, while PoE+ encompasses Class 0 through Class 4, in which a larger amount of power can be sourced from the PSE, almost twice as much as that of PoE – 25.5W.
New PoE Standard Paves the Way for High-Power PTZ Cameras
For almost two decades, PoE and PoE+ have been widely used to power low-voltage security cameras over twisted pair cabling. But as the application of PoE continues to grow with the advancement of new camera technology, these two PoE standards gradually started to fall short when dealing with high-power appliances. To satisfy the growing power requirements of today’s high-power PTZ cameras, a new-generation PoE standard called IEEE802.3bt was finally ratified in 2018. It’s the first-generation PoE standard that implements power over four twisted pairs of the Ethernet cable and offers the highest power capabilities of all PoE types currently in existence. As previously mentioned, in IEEE 802.3af/at, only two twisted pairs are used for power transmission, but IEEE802.3bt uses all 8 wires to transport power so as to minimize power loss over the cable length, so it is also known as 4 Pair PoE.
Uses for IEEE802.3bt
The newest PoE standard is fully backward compatible with the prior PoE standards and can be used to support more power-hungry applications including:
• Smart building and infrastructure like LED lighting
• High-power network devices such as POS terminals, RFID readers and digital signage
• High-performance network devices like WiFi6 access points
• Security camera system (PTZ cameras) and video conference system
What’s New in IEEE802.3bt Standard?
When designing a CCTV system, it’s easy to underestimate the power consumption of the security cameras, but the latest IEEE802.3bt standard can provide adequate power to the PTZ cameras without added infrastructure or costs. It not only guarantees a higher power output but also brings lots of new features to the PoE standards.
New Types and Classes
The new-generation PoE IEEE802.3bt is updated with 2 new types (Type 3 and Type 4) and 4 new classes (Class 5-8). Type 3 (PoE++) is specified to deliver a maximum power of 60W at each PoE port over Cat5 cabling- twice the capacity of PoE+. Examples of devices that these higher levels of power support include 802.11ac WAPs, PTZ cameras with heaters, digital signage, Touch-Screen PCs, etc. Type 3 covers and extends the classes in Type 1 and Type 2 and also introduces two new classes of Class 5 and 6 to the power system with a minimum of 51W available at the PD in Class 6. PoE++ can support at least Class 4 in 2 or 4 twisted pairs and Class 5-6 in all 4 pairs.
Conforming to the newest IEEE802.3bt standard, Type 4, commonly known as Hi-PoE, can generate a much higher power output of 90-100W at the PSE with a minimum power assured on each port being 71.3W over Cat6/6e cables to support extremely power-hungry devices like flat screens, video conferencing equipment, desktop computers, etc. With the exception of legacy Classes 0-6, Type 4 is also able to support Classes 7-8 with the minimum power at the PD being 71-90W. But even though Type 3 and Type 4 could deliver a much higher amount of power to the network devices, they’re still restricted to the 100-meter distance limitation of standard PoE.
Single and Dual Signature
Apart from the new PoE types and classes, the 802.3bt standard also introduces 2 new PD typologies, i.e. single signature and dual signature, to the world of PoE. The main difference between these two typologies is that the PD that supports the single signature shares the same detection, classification and maintain-power signatures between both pair sets, while the dual signature PD employs different signatures on each pair set, so it has independently different signatures between two pairs with distinct supported loads and power classes. The previous PoE standards IEEE 802.3af/at cannot distinguish single-signature PDs from dual-signature ones, whereas the new IEEE standard enables the differentiation between these two types of devices via connection check. In a PTZ camera that supports dual-signature, one pair can be connected to the camera, while the other pair can be connected to the heater, PTZ motor or infrared illuminators to realize optimal power distribution.
Lower Standby Power
The new PoE standard shows great improvements in the standby power consumption. In the IEEE 802.3af/at standards, the PDs must draw approximately 10mA for at least 75ms every 250ms in a duty cycle to keep the PoE port alive, which is extremely crucial for LED lighting and security systems to remain “ON” to ensure fast turn-on. Unlike traditional lighting, the intelligent LED ballasts need to be constantly powered even when the light is off, but it also results in significant power wastage when a large number of PDs are deployed. IEEE 802.3bt offers a practical solution to reduce the minimum standby power to 20mW which is 10 times lower than the older IEEE standards (nearly 200mW at 54V).
Auto-class and Extended Power
Auto-class helps optimize the power output of the PSE to ensure system efficiency. It allows the PSE to determine the actual maximum power drawn by the connected PD and the actual cable length used and set the power budget to precisely match that level. There’s always some power budgeted for heat dissipation or DC resistance over longer cable runs, but the extended power feature of the high-power PoE makes sure each connected PD can use the maximum available power based on the cable’s actual resistance and evens allows the input power to reach up to 90W when the cable length is known.
High-Power PoE Opens Up Various Power Options for PTZ Cameras
With the advent of high-power PoE emerges various types of PoE solutions. It also opens up a new world of power options to simplify camera installations in remote places. In this section, we’ll introduce four ways to install the PTZ cameras.
1. Power One PTZ Camera with a PoE++ Injector
The most direct and simple way to power the PTZ camera is using a high-power PoE injector. It’s a perfect choice when only a few devices are installed since the PoE injector can only power one device at a time. The PoE++ injector can supply more energy to power-hungry devices at a higher output since only one device is connected. It is very easy to manage and troubleshoot, making it ultra user-friendly for both residential and commercial applications. It also works well with legacy network devices: by connecting the PoE++ injector to a regular network switch, you can mix the PoE and non-PoE devices on the same network, eliminating the need and cost of installing new infrastructures.
Normally, 40W is enough for a PTZ camera equipped with heaters and considering the device is normally installed outdoors, a waterproof PoE++ injector is highly recommended for the setup. FASTCABLING has launched a 60W outdoor industrial waterproof PoE injector (IP67 waterproof) to help you set up the high-power PTZ cameras in extreme weather conditions. Compliant with the IEEE802.3bt (Type 3), it supports a maximum power supply of 51W at the PD with a wide input voltage range of DC24~56V. It has a built-in regulator that will boost up the power to regulated DC54V to reduce voltage drops in long-distance applications.
2. Manage Multiple Devices with an 802.3bt PoE Switch
When you need to install more than three cameras at the installation site, the PoE switch is definitely your best pick. It offers great flexibility for installation in places where there is no power source present, which greatly improves the scalability of your network and reduces the installation costs. The PoE switch provides more PoE ports to allow you to install more than one PTZ camera at the edge. It also provides centralized power management to guarantee the normal function of each camera. And it’s highly scalable: by connecting to another PoE switch, the Ethernet ports can be easily expanded within minutes. In addition, an active PoE switch is also equipped with auto-sensing ports that automatically detect the compatibility of the connected devices to reduce the chances of power outages, operation failures, etc. So if a PTZ camera accidentally goes offline, you will get immediately notified and automatically adjust to compensate from the control room.
We’ve launched an 8-port visual PoE managed switch that can supply a maximum power of 60W on ports#1-4 (30W max. on ports#5-8). It comes with two Gigabit SFP slots to deliver a fast-speed, low-latency network connection in long-distance applications. The built-in LCD screen exhibits the real-time condition of the PoE switch and allows you to easily manage each individual port. By supporting Layer 3 IPv4 or IPv6 dual-stack and various management functions, this visual PoE++ managed switch helps small businesses to step into the IPv6 networks with the lowest investment. It is loaded with QoS features to prioritize and monitor the traffic coming out of each PoE port and enhance the bandwidth management to improve user experience and ensure better response time, particularly useful for enterprise networks.
3. Long-Distance Setup with PoE Extenders
Theoretically, PoE can power any compatible device at any reasonable distance if sufficient voltage reaches the PDs, but it’s only designed to work over a maximum distance of 100m. Signal degradation and power loss will gradually intensify as the distance increases and eventually shut down the system. And the newest IEEE802.3bt standard is no exception. To overcome the geographical limit of standard PoE in high-power applications, one option is to use a PoE++ extender. Unlike the RJ45 coupler, it can repeat and re-transmit the signals along the long cable runs and pass the remaining power to the next PoE device (normally, a Gigabit PoE extender will only consume 4-5W) so as to eliminate the deployment of any active devices down the line. In general, it is a plug-and-go technology, and it works so seamlessly that the installer won’t even know its existence. To learn more about PoE extension, continue to read The Myths and Truths about PoE Extension-Long Range Ethernet.
To facilitate long-distance network deployments in outdoor environments, we’ve launched an outdoor waterproof 802.3bt Gigabit PoE extender to help you install the PTZ cameras more than 100 meters away from the control room. It supports a power budget of 60W max., and the power available at the PD will still remain at 51W in approximate. By daisy-chaining 2 units at a time, you can extend the distance up to 300 meters. Most importantly, this PoE extender is equipped with 2 PoE interfaces to allow you to set up two security cameras at once (a PTZ camera: 20~40W and a fixed IP camera:4~5W). But in outdoor applications, precautionary actions should always be taken to protect the devices from lightning strikes, especially crucial for mission-critical applications like security camera systems. Even though electrical surges are largely environmentally impacted, it’s possible that lightning strikes will induce on data lines and fry the circuits of the connected devices. So when running long copper cables, remember to install a set of surge protectors to safeguard your network.
4. Mix PoE and Non-PoE Devices with a PoE Splitter
Considering not all PTZ cameras are PoE-enabled, the PoE splitter provides a cost-effective solution to power a non-PoE device by splitting PoE from a unified network cable and delivering power and data through separate connections. It often works with a PoE switch or a PoE injector to power non-PoE devices in hard-to-reach areas where is hard to find a power outlet, eliminating the need for additional AC wiring. It is often used in two scenarios: 1) in situations where you need to connect a PSE, endspan or midspan, with a non-PoE-capable device; 2) or to install non-PoE devices with a regular switch in remote locations where no power source is present. The PoE splitter can also be used to bring a 48V DC down to a low voltage electrical current (regulated 5, 12 or 24V), enabling the safe connection to devices with a low input voltage range.
Fastcabling’s high power 802.3bt outdoor waterproof PoE++ splitter is an industrial-grade device suitable to power non-PoE devices that in harsh environments. It often works with a PoE injector or PoE switch enabling a maximum of 60W output power on each port. This PoE++ splitter is backward compatible with IEEE802.3af/at to work with legacy Type 1 and Type 2 network devices. It features 6KV surge protection to prevent electrical damage caused by lightning strikes, able to work under a vast temperature range from -40℃ to 75℃.
Last Thoughts
Power Demotion: Most PSEs don’t have the ability to deliver the full power that the PDs request. And in this case, the PSE will still power the PDs but with less power than is requested because it will demote the devices to a lower type. For example, a PD requests Class 8 power but the PSE only supports Class 6, and then the PD will be automatically demoted to Class 6. To ensure full compatibility, you should check the power class of the PTZ cameras and the PSE and make sure they belong to the same power level, or the PSE will shut down the device for drawing too much power.
Avoid Overheating: Heat rise is a severe concern in high-power PoE. Simply put, more power means more heat, and overheating will increase the DC resistance in copper wires, thereby jeopardizing the signal transmission. It will also accelerate the deterioration of the cables and increases the insertion loss. To minimize heat rise in high-power PoE, you should choose a network cable of a higher category: the higher the cable category, the lower the heat rise. Normally, a Cat6 or 6e Ethernet cable would suffice the job. And you can choose a cable terminated with a larger conductor since conductor resistance is one of the main culprits of overheating. A larger conductor will let electrical currents easily flow through and thereby reduce the conductor resistance. And it’s advised to choose a shielded cable rather than an unshielded one for better heat dissipation.
Backward Compatibility: The IEEE802.3bt standard is fully backward compatible with the prior PoE standards, which means the 802.3bt equipment will be able to send power to the 802.3at devices with no issues. And it helps higher-standard devices blend into the legacy network systems. But problems come when you mix PoE, PoE+ and PoE++ devices on the same network. For example, if you connect a PoE++ (60W, Class 6) injector to a PoE+ extender (30W, Class 4), the power class will also be demoted to Class 4 accordingly since the PoE+ device can only accept 30 watts of power max., so the power received at the PD will be less than 30W considering the power loss over long cable runs. So you should choose the PSE and PDs that share the same PoE standard.
