Which Ethernet wires carry power?

Ethernet is a widely used networking protocol that enables the seamless transfer of data within a network. With the increasing popularity of Ethernet, a rising need for Power over Ethernet (PoE) has arisen. PoE allows the transfer of power along with data over Ethernet cables. This technology has made the installation of network devices much easier and cost-effective by eliminating the need for separate power cables.

However, not all Ethernet cables carry power across them. So, which Ethernet wires carry power? Let''s dive in and find out.

What is Power over Ethernet (PoE)?

PoE is a technology that allows electrical power to be transmitted over Ethernet cabling, along with data. It’s a simple way to connect devices to a network without requiring a separate power source. PoE technology is used in a wide range of applications, including Internet Protocol (IP) cameras, wireless access points, and Voice over Internet Protocol (VoIP) phones.

Types of Power over Ethernet (PoE)

There are two types of PoE: PoE and PoE+. Here’s how they differ:

- PoE: The original PoE standard, also known as IEEE 802.3af, provides up to 15.4 watts of power over each cable.

- PoE+: A newer standard, also known as IEEE 802.3at, provides up to 30 watts of power over each cable.

How Power over Ethernet Works

PoE-enabled devices have two types of ports: Data-in and Data-out. The former port receives both data and power from a PoE switch or injector, while the latter only receives data.

PoE injectors or switches connect to network devices such as wireless access points, security cameras, and VoIP phones via Ethernet cables. They also provide power to these devices over the same cables, eliminating the need for separate power cables.

PoE-enabled devices have built-in circuitry that splits the incoming power from the data stream. The power is then used to power the device, while the data is used to transmit network traffic.

Which Ethernet wires Carry Power?

PoE uses two pairs of wires in an Ethernet cable to transmit power:

- Pins 1 and 2

- Pins 3 and 6

These wires are used to send data in a standard Ethernet cable, but in a PoE setup, they’re also used to transmit power.

PoE Standards

PoE has a set of standards that define the maximum amount of power that can be delivered over an Ethernet cable.

- IEEE 802.3af: This standard provides up to 15.4 watts of DC power to each device.

- IEEE 802.3at: Also known as PoE+, this standard provides up to 30 watts of DC power to each device.

PoE and Non-PoE Devices

Not all Ethernet cables support PoE. Non-PoE Ethernet cables only have two pairs of wires, while PoE Ethernet cables have four pairs of wires.

Non-PoE devices can be connected to PoE switches or injectors, but they won’t receive any power. PoE devices can be connected to non-PoE switches, but they won’t receive any power either.

Conclusion

In conclusion, not all Ethernet wires carry power. PoE uses pins 1 and 2 and pins 3 and 6 to transmit power along with data over Ethernet cables. PoE is a simple and cost-effective way to power network devices, but it’s important to use the correct Ethernet cables and PoE devices to avoid any potential issues.

By understanding which Ethernet wires carry power, you can design, install, and maintain your network devices safely and efficiently.