**Which wires are used for power in a POE network?**
POE, or Power over Ethernet, is a technology that allows existing Ethernet cabling—typically CAT5 or higher—to deliver both data and electrical power to IP-based devices without the need for separate power cables. This makes it a cost-effective and efficient solution for powering devices like IP phones, wireless access points, and surveillance cameras.
POE works by sending DC power through the same Network Cable that carries data. The standard voltage for POE is 48V DC, and it can effectively supply power up to a distance of 100 meters, which aligns with the maximum length of Ethernet cables. This means you don't have to worry about signal degradation or power loss over short distances.
A typical Ethernet cable has eight wires, grouped into four twisted pairs. There are two main methods used to deliver power through these wires: Mode A and Mode B.
In **Mode A**, power is delivered using the unused pairs of the cable—specifically the 4th and 5th wires (blue and white/blue) for the positive, and the 7th and 8th wires (brown and white/brown) for the negative. This method is often used in older POE standards.
In **Mode B**, power is delivered through the same pairs used for data transmission. This includes the 1st and 2nd wires (orange and white/orange) for the positive, and the 3rd and 6th wires (green and white/green) for the negative. This method is more common in modern POE implementations, as it allows for higher power delivery and better compatibility with data traffic.
According to the IEEE 802.3af standard, the voltage range for POE is between 44V and 57V DC. The newer IEEE 802.3at standard increases this range to 50V–57V DC, allowing for higher power output. Most devices today use the 1-2-3-6 pair for data transmission and the 4-5 and 7-8 pairs for power delivery, ensuring reliable operation while maintaining compatibility with standard networking equipment.
Network Cable
Network Cable
Standard: ISO/IEC 11801, TIA/EIA 568-C.2,
Conductor: Bare copper
Insulation: HDPE
UTP/FTP: Unshield or Aluminum/PET-Foil Bonded & Tinned Copper braid
Sheath: PVC (Polyvinyl Chloride)
Applications: Those Communication Cable are used mainly for data transmission
Network Cable,Cablelink Communications,lan Cable,Straight Through Cable
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