PoE is a mechanism that enables power to be delivered to connected devices using the installed data cables, thus eliminating the requirement to provide power at the device location. This has numerous benefits, including a reduction in the amount of cable that needs to be installed and the ability to power devices that are not close to any existing power source.
There are two key components for delivering PoE
1. Power Sourcing Equipment (PSE)
There are two types of Power Sourcing Equipment
- End span
- power is injected by the switch
- Mid span
- power is injected by a standalone device that sits between the switch and the
The PSE initially applies a low voltage on the wires and a valid PD will present a specific signature to the PSE. If no valid signature is detected the PSE will NOT send power but will still pass data. If a valid signature is detected then the PD may optionally present a classification signature. Upon completion of the detection process, power is supplied by the PSE.
There are various different levels of power that can be provided by PoE, a summary of which is provided below:
- TSB-184-A contains guidance on contact design and IEC 60512-99-001 is referenced as a
suitable test regime
The demand for high power PoE and high data transmission rates means that Cat 6A cables should be installed to Wireless Access Point locations.
When procuring cabling components look for independent certification to IEC 60512-99-001.