Power over Ethernet (PoE) is a common method for powering devices like VoiP phones, Wireless access points, and Security cameras because it transmits power over the same line as data. By not requiring a separate power outlet to be installed, generally results in significant savings.
The majority of PoE used today is IEEE 802.3af PoE or the more effective IEEE 802.3at PoE+, both of which are extremely safe due to the fact that the power source equipment (PSE) doesn’t add power to the data line unless it detects a compatible powered device (PD) connected to the other end of the cable. Devices that do not support PoE are protected by this. Power requirements are also negotiated between PSEs and PDs, ensuring that no PD ever has too much power. To reduce the risk of shock, both PSEs and PDs include power supplies and regulators that are insulated from the ground.
The next standard for PoE coined IEEE 802.3bt PoE++ was developed and established in 2016-17.
Here’s where things get difficult.
Because most PoE accessible today is standards-based 802.3af or 802.3at (and 802.3bt getting more common), it’s easy to overlook versions of PoE that aren’t. Some of these non-standards-based PoE implementations include power injectors that deliver power without first ensuring compliance, which can be fatal for clueless network equipment.
Proprietary PoE, high-wattage proprietary PoE, and passive PoE are the three main types of non-standard PoE.
Proprietary PoE
Prior to the approval of the 802.3af standard in 2003, PoE was a free-for-all, with several suppliers offering their own method of supplying power over data lines. Some vendors continue to provide their own proprietary PoE. There are different levels of communication between PSE and PD offered by these proprietary solutions.
High-wattage Proprietary PoE
High-wattage proprietary PoE (Power over Ethernet) is a type of PoE technology that allows for the transmission of higher levels of power over Ethernet cables. Unlike standard PoE, which provides up to 15.4 watts of power per port, high-wattage proprietary PoE systems can provide up to 25-60 watts of power per port.
This higher power level allows for the operation of devices that require more power, such as high-power wireless access points, PTZ (pan-tilt-zoom) cameras, and LED lighting systems. High-wattage proprietary PoE systems are typically used in applications where standard PoE is not sufficient to power the connected devices.
One disadvantage of high-wattage proprietary PoE systems is that they are not standardized, and are often proprietary to a specific manufacturer or vendor. This means that they may not be compatible with devices from other manufacturers, and may require the use of specialized cables and connectors. Additionally, they may be more expensive than standard PoE systems.
Overall, high-wattage proprietary PoE systems can be a useful solution for applications that require higher levels of power over Ethernet cables, but it is important to carefully consider the potential disadvantages before implementing such a system.
Passive PoE
Passive PoE (Power over Ethernet) is a type of PoE technology that allows for the transmission of power over Ethernet cables without the use of active electronics. In passive PoE, the power is transmitted over the unused pairs of wires in the Ethernet cable and is separated from the data signals by a passive splitter at the device end.
There are several advantages to using passive PoE. Firstly, it is a simple and cost-effective solution, as it does not require the use of active electronic components such as power injectors or power-sourcing equipment. This makes it easy to implement and maintain and can be a good option for small or medium-sized networks.
Another advantage of passive PoE is that it is compatible with any standard Ethernet cable, and does not require the use of specialized cables or connectors. This makes it easy to use with existing network infrastructure and devices.
However, there are also some limitations to passive PoE. It is only suitable for low-power devices, as it can only provide a limited amount of power. Additionally, it is not as efficient as active PoE, as some power is lost in the transmission over the Ethernet cable.
Overall, passive PoE can be a useful solution for certain applications, but it is important to carefully consider its limitations and potential disadvantages before implementing it in a network.
Labels and Documentation
There is nothing wrong with PoE that is not based on standards; various power techniques for network devices function just as well as 802.3af/at/bt PoE. However, you must be aware of the type of Power over Ethernet you have and the compatible devices. The keys to knowing that, for example, the power injector is a high-wattage proprietary injector that will fry the IP camera you’re about to install are good network documentation and labelling. Proper documentation, which is always a good idea, becomes critical when you have components that may interfere with or harm other components.