Power over Ethernet or (PoE), is the method of passing electrical power simultaneously with a data signal on the same Ethernet cable to a connected device.
The initial devices that carry the electrical power and data over the Ethernet cable are called Power Sourcing Equipment or (PSE). These devices are typically a Power over Ethernet Switch or Midspan PoE Injector.
Most often you come across the need for PoE technology when you do not have local AC power outlets or sockets available. So for example, an installation for a PoE IP Camera or PoE Access Point that is placed outdoors, away from any nearby electrical outlets or sockets, with PoE you can use either existing Ethernet cabling or run new conduit and have PSE like a PoE switch to provide power and data to the desired devices thus saving you time and money without having to install power at the remote device end.
These remotely connected devices can range from PoE IP Cameras, PoE Access Points, PoE Microwaves or Radios, PoE Switches, PoE Access Control Systems, PoE LED Lightning, and PoE VoIP Phones.
IEEE PoE 802.3 / PoE+ 802.3at / PoE++ 802.3bt Standards
There are a few different flavors of PoE when it comes to distinguishing the power specifications of PoE devices. Usually they are tiered as Type 1, Type 2, Type 3 and Type 4. The list below explains the various types:
► IEEE 802.3af-2003
► Known as PoE, power is delivered over 2-pairs of wiring
► Provides up to 15.4 watts of DC power
PoE Type 1 uses 2 pairs of wiring to provide up to 15.4 watts of DC power to each PoE port (12.95 watts for each device) on VoIP Phones, PoE IP Cameras, WiFi Access Points or Access Control Systems.
► IEEE 802.3at-2009
► Known as PoE+, power is delivered over 2-pairs or 4-pairs of wiring
► Provides up to 30 watts of DC power
PoE Type 2 uses 2 or 4 pairs of wiring to provide up to 30 watts of DC power to each port (25.5 watts for each device) on PoE Pan Tilt Zoom (PTZ) IP Cameras, WiFi Access Points, and other higher powered devices. Type 2 is also cross compatible with Type 1 PoE devices.
► IEEE 802.3bt-2013
► Known as PoE++, 4P PoE, 4-pair PoE, power is delivered over 4-pairs of wiring
► Provides up to 60 watts of DC power
PoE Type 3 uses 4 pairs of wiring to provide up to 60 watts of DC power to each port (51 watts for each device) on PoE Pan Tilt Zoom (PTZ) IP Cameras, WiFi Access Points, and other higher powered devices.
► IEEE 802.3bt-2017
► Known as PoE++, Higher-power PoE, power is delivered over 4-pairs of wiring
► Provides up to 100 watts of DC power
PoE Type 4 uses 4 pairs of wiring to provide up to 100 watts of DC power to each port (71 watts for each device) on PoE Pan Tilt Zoom (PTZ) IP Cameras, WiFi Access Points, laptops, and TVs.
Passive PoE is a whole other animal since it doesn’t fall under any of the IEEE standards listed above. Typically, manufacturers of PoE products will develop their own flavor of PoE and incorporate it into their products and PSE devices. So when you purchase a PoE IP Camera or PoE WiFi Access Point, they either charge you extra for their proprietary PSE modules or in very few cases, supply the PSE bundled with the PoE device that you purchase. Oftentimes, passive PoE devices do not have Power Detection which means that you either must purchase their proprietary PSE modules or make sure you purchase PSE devices that match the power specifications exactly to the PoE device you are trying to power on. This can cause a lot of grief as you would expect manufacturers to develop products that follow industry standards, however this is turning out to not be the case. Rather than conform worldwide standards in the industry, manufacturers are forcing you to buy their proprietary products to fill their pockets and leave the customers hanging.
Thankfully, Enable-IT prides itself on designing, supporting, and manufacturing, made in the USA, professional grade, industry standard technologies and is constantly researching and staying ahead of the competition in every aspect whether that be our Lifetime Warranty, 45 Day Money Back Guarantee, Gigabit Ethernet & PoE Extension Products, English-speaking Sales and Support Team, and custom OEM capabilities.
When operating PoE devices beyond the IEEE 802.3 Ethernet distance limitation of 328ft or 100m, PoE extenders from Enable-IT, Inc. will allow you to drive Ethernet data communications and PoE to distances over 4,000ft or 1.2km. However, if powering on a passive PoE device at distance, you need to use a PoE Reducer or PSE device that matches the power consumption of the PoE device identically.
If you find yourself guessing or running into problems with powering PoE devices, make sure to contact Enable-IT Customer Support for expert sales and support service!