September 09 2021

A Comprehensive Guide for Safe Deployment of Power-over-Ethernet (PoE)

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With the passage of time, companies have realized the importance of effective data transmission. This is why the installation of power-over-Ethernet (PoE) has become quite common in business premises. The use of this technology enhances data transmission effectiveness and reduces operating costs as it only requires one cable instead of two separate cables for network and power.

Suffice it to say, PoE offers many benefits over traditional cabling systems. It’s safe, reliable, flexible and expandable. Also, it can be used for many devices. But, you would need the best cables from reliable fiber optic cable suppliers in Dubai to obtain all these benefits.

Also, a power-over-Ethernet system is only effective if it’s deployed safely. For the uninitiated, numerous measures have to be taken care of for ensuring its safe operation and prevention of hazards caused by electrical power. Doing this will also guarantee the protection of legacy equipment against damage.

Let’s take a look at some of these safety measures associated with the installation of power-over-Ethernet:

Safety Measures for The Installation of Power-over-Ethernet (PoE)

Current Limiting

This measure is adopted to prevent PSE from overloading. It also helps to quickly disable power devices that malfunction. As per this approach, a particular upper limit for current is set for every port. The current is continuously measured, and as soon as it increases the upper limit, the power is disconnected.

Signature Detection

This safety measure for the installation of power-over-Ethernet prevents legacy devices from getting damaged as the cable only gets PoE voltages once the system detects a compatible powered device.

Polarity Protection

The power input circuitry of a powered device contains bridges that are responsible for polarity protection. This safety measure allows the system to receive power irrespective of the cable’s polarity and configuration. So, whether it’s reverse connections or incompatible equipment, there’s no harmful impact on the cable. They will either work or not work at all. The risk of damage caused by badly-wired equipment doesn’t prevail.

Automatic Disconnection

Devices are automatically disconnected when the current level goes below the minimum set level. The cable, in such a scenario, returns to its original state. And you can connect it to another device without any issue.

Efficient and Safe Voltage

Power-over-Ethernet features a safe level, up to 57 volts. It is adequate enough to efficiently transmit power while being safe at the same time.


Incompatible power suppliers that have exposed power connectors cannot be used with PoE. This further enhances the safety of the system.

Impact of PoE on Data Cables & Connectors

Impact on Connectors

When the power flows through a patch cord plug or RJ45 connector, it dispels heat. Although it doesn’t overheat and no damage is caused to the connector, its contacts are prone to get damaged. When the connector is disconnected from the socket, it generates arcing. This results in the corroding of the contact’s protective gold plating. This, in turn, leads to attenuation and, thus, the connection fails completely.  

This loss of increased attenuation or connection can be avoided by selecting connectors that have thicker gold plating during the installation of power-over-Ethernet. Also, the contact and disconnection parts of the connector should be separate.

Impact On Cables

It’s a known fact that the amount of power that a twisted pair cable carries reduces as it reaches the end device. This, however, isn’t exactly the loss of power since the power actually converts into heat. This phenomenon takes place due to the Joule effect.

When the cable carries a higher level of power, it generates a higher amount of heat. As these cables are installed in bundles, the ones in the center heat up more as compared to others. This leads to the rise in the temperature of the cable.

Apart from this factor, there are numerous other reasons that impact the cable temperature. These include

  • Power-over-Ethernet Type: There are four types of PoE available, namely Type 1, Type 2, Type 3 and Type 4. The higher type has a higher temperature.
  • No. of Cables in a Bundle: if there are more cables in a bundle, the temperature will increase.
  • The Type of Cable: Shielded cables are known to dispel heat better as compared to unshielded ones.
  • DC Resistance: The cabling channel’s DC resistance also impacts the temperature. For instance, Cat 5e has higher resistance in comparison to Cat 6A variants as the latter has thicker conductors.
  • The location of Cables: Cables lying in closed tray baskets tend to heat up more as compared to the ones in open trays.

How to Reduce the Impact of PoE on Copper Cabling Systems?

Follow these recommendations when during the designing and installation of power-over-Ethernet to limit the impact of high-power PoE:

  • Choose open basket trays instead of closed trays for pathway systems.
  • Prefer shielded cables over unshielded ones. This is recommended as the metallic foil they contain dissipates the heat more efficiently.
  • Don’t have more than 24 cables per bundle. However, if you’re using shielded Cat6A or Cat7A, you can limit the bundle to 48 cables.
  • Make sure cables are kept away from equipment that generates heat.
  • Opt for higher-category cables as they heat up less in comparison to lower-category ones.

A Final Word

Following these recommendations will ensure safety during the installation of power-over-Ethernet. For better results, it is recommended to consult leading IT solutions company in Dubai.