The maximum distance to power devices over Power over Ethernet (PoE) using standard Unshielded Twisted Pair (UTP) cable, such as Cat5e or Cat6, is approximately 100 meters (328 feet).

This distance limit is based on standard Ethernet specifications to ensure proper and reliable data communication.

However, it is important to consider that PoE efficiency can be influenced by several factors, including cable quality, power consumption of the powered device, and the capacity of the PoE injector or switch.

At greater distances, there may be a significant voltage drop that could affect the performance of the powered device. For distances close to the maximum limit, be sure to use high-quality cable and verify that the PoE equipment is capable of compensating for the voltage drop along the cable.

For situations where you need to extend the distance beyond 100 meters, there are some solutions, such as:

1. Use PoE Extender: PoE extenders allow you to increase the power and data transmission distance beyond the standard 100 meters, being able to chain several extenders depending on the specific need and the extender model.
2. Use Cascaded PoE Switches: Installing additional PoE switches along the cabling can be used to regenerate the signal and provide power over longer distances.
3. Medium PoE Converters: In cases where significantly greater distances are needed, media converters can be used that convert the Ethernet signal to fiber optics for the long run and then back to Ethernet near the device, using PoE for the last run.

Whichever method is chosen, it is always crucial to perform adequate planning and testing to ensure that the solution meets the power and data requirements of the device to be powered.