The typical voltage range for Power over Ethernet (PoE) switches is between 44V and 57V, with 48V being the most commonly used voltage.

Voltage Standards

1. IEEE 802.3af (PoE): This standard specifies a voltage range of 44V to 57V with a maximum power output of 15.4 watts per port. It is suitable for devices with lower power requirements, such as VoIP phones and basic IP cameras .

2. IEEE 802.3at (PoE+): This enhanced standard allows for a voltage range of 50V to 57V and increases the maximum power output to 30 watts per port. It supports more demanding devices, such as advanced IP cameras and high-performance wireless access points .

3. IEEE 802.3bt (PoE++): This standard further extends the capabilities, offering two types: Type 3 provides 50V to 57V with up to 60 watts per port, while Type 4 supports 52V to 57V with a maximum of 90 watts per port. This is ideal for high-power applications like video conferencing systems and networked displays .

Importance of Voltage Range

• Device Compatibility: The specified voltage ranges ensure compatibility across various devices, allowing for seamless integration into existing network infrastructures.
• Power Efficiency: Operating within these voltage ranges helps maintain power efficiency and reduces the risk of voltage drop over long cable runs, which is crucial in industrial and large-scale deployments .
• Safety: The voltage levels used in PoE are considered safe for human interaction, making it a reliable choice for powering devices in various environments .

In summary, when selecting a PoE switch, it is essential to consider the voltage range and power output to ensure compatibility with the devices you intend to power. The most common voltage used is 48V, which is supported by the majority of PoE devices.