Exploring the Functionality of a PoE Injector ?
A PoE injector facilitates the connection of your PoE-enabled network device to a non-PoE LAN switch port. In practical terms, a PoE injector can serve to link various devices such as wireless access points, IP phones, network cameras, or any IEEE 802.3af/at-powered device (PD) to a network switch. By utilizing a PoE injector, you eliminate the necessity of installing additional AC power lines for your wireless access point, network camera, or IP phone. Instead, you leverage the existing LAN cabling to transmit both DC power and data efficiently.
How much power (W) can it provide?
IEEE-compliant PoE injectors are able to output anywhere from 12 watts to over 70 watts of power.
PoE Standard |
PoE Common Name |
Power Output |
Comment |
|---|---|---|---|
|
IEEE 802.3af
|
PoE
|
15.40 Watts
|
12.95W power available for connected device (PD)
|
|
IEEE 802.3at
|
PoE+
|
30 Watts
|
25.50W power available for connected device (PD)
|
|
IEEE 802.3bt Type 3
|
4P PoE, Ultra PoE
|
60 Watts
|
51W power available for connected device (PD)
|
|
IEEE 802.3bt Type 4
|
Ultra PoE
|
100 Watts
|
71 W power available for connected device (PD)
|
What kind of cable do I need?
PoE injectors adhere to the guidelines established by the IEEE 802.3 working group, eliminating the need for specialized cabling. It is important to note that Ultra-PoE connections necessitate 8-pin network cabling. While most networking cables are 8-pin, exceptionally inexpensive cables may only contain 4 pins.
PoE Standard |
Minimum Cable Category |
Power Pins required |
Supported Modes |
|---|---|---|---|
|
IEEE 802.3af
|
Category 3
|
4-pins / 2-pairs
|
Mode A, Mode B
|
|
IEEE 802.3at
|
Category 4
|
4-pins / 2-pairs
|
Mode A, Mode B
|
|
IEEE 802.3bt Type 3
|
Category 5
|
8-pins / 4 pairs
|
4-pair
|
|
IEEE 802.3bt Type 4
|
Category 6
|
8-pins / 4 pairs
|
4-pair
|
Can I use CCA Cable?
CCA stands for Copper-Clad Aluminium. CCA cabling, also known as Cu/Al, features an aluminium core coated with copper, which differs from standard network cabling that utilizes 100% copper for the conductor. Typically, the cost of CCA cabling is lower than that of network cables made entirely from copper. While there is a wealth of information (and misinformation) online regarding the drawbacks of CCA cables, it is worth noting that CCA cables generally perform adequately for standard networking applications. However, we advise against using them in conjunction with PoE injectors or switches.
Why can't I use CCA cables with PoE?
Can you use CCA network cables with PoE? Technically, yes, you can. However, should you? No. Aluminum (or aluminum, depending on your preference) is not as effective an electrical conductor as copper. This is primarily due to the higher DC-resistance of aluminum compared to copper cable. The increased resistance in CCA cable results in more power being lost and dissipated as heat. Furthermore, the longer the cable connection, the more pronounced this issue becomes. The heightened heat generation and power loss are significant concerns associated with CCA cables. In summary: To prioritize safety and performance, it is recommended to opt for 100% copper network cabling from your supplier.
Is using a PoE Injector safe? Can it damage my equipment?
IEEE 802.3af/at/bt compliant PoE injectors are designed with a high level of safety in mind. They are engineered to safeguard connected equipment, even if the devices are not specifically designed for PoE applications. Before delivering power to the connected powered device (PD) like a VoIP phone, the PoE injector initiates a handshake process. This procedure involves using low voltage, ensuring it is harmless to all connected devices, regardless of their PoE compatibility. Throughout the handshake, crucial parameters are established, particularly concerning the power requirements of the connected device. Once the handshake is successfully completed, the PoE injector commences power delivery, prompting the connected device to activate. If the handshake fails for any reason, the PoE injector will not transmit power. This inherent feature of all IEEE 802.3af/at/bt-compliant devices underscores the safety of this technology.
What are the advantages of using a PoE Injector?
PoE technology offers numerous advantages.
Firstly, the integration of data and power transmission over a standard Ethernet cable eliminates the need for AC/DC power supplies and outlets. This not only reduces costs, as no electrician is necessary for installing new devices in areas lacking power sources, but also benefits from the availability of affordable Ethernet networking cabling that is often pre-installed in the location.
Secondly, while not directly related to PoE injectors, PoE technology as a whole minimizes points of failure. By connecting your PoE switch to an uninterruptible power supply (UPS), you ensure consistent power delivery to PoE powered devices. This feature is especially crucial for maintaining continuous power supply to mission-critical devices such as PoE security cameras.
Lastly, PoE installations utilizing managed PoE switches allow for remote restarts of connected PoE devices, either manually or according to a preset schedule. Modern PoE switches are equipped with a watchdog function, such as the Powered Device Manager (PDM), which significantly reduces downtime for connected devices.