How much DC voltage does Power over Ethernet (P.O.E.) allow over two unused wires?

Power over Ethernet (P.O.E.) technology allows electrical power to be transmitted along with data over standard Ethernet cables, specifically utilizing unused pairs of wires in a cable. The standard voltage for P.O.E., particularly in widespread applications, is 48V DC. This voltage level is specified to ensure that devices requiring power, like IP cameras, VoIP phones, and wireless access points, receive sufficient energy for operation while remaining within safe limits for typical networking equipment.

It is important to note that P.O.E. adheres to IEEE 802.3 standards, which detail this voltage requirement to facilitate consistent operation across various devices and manufacturers. The selected voltage effectively balances the need for ample power delivery with the constraints of network infrastructure, ensuring efficiency and safety. Therefore, 48V DC becomes the correct and standard choice in this context.