Guidance for power consumption of PoE Device

In the IEEE802.3af standard, PSE (Power Sourcing Equipment) can achieve the output power of 15.4W, during power transmission, there is voltage drop problem, PD (powered device) can obtain 12.95W input power averagely. In IEEE802.3at standard, PSE power supply device can maximum output 30W power. In real usage, after the current increases, the power consumption loss increases accordingly, thus IEEE802.3at requires Cat5 Ethernet cable to reduce the power consumption during transmission, PD can also obtain 25.5W input power.

Power sourcing equipment (PSE) can transfer both data and electrical power to powered devices, it's the core component for cost-effective Power over Ethernet system. The common PSE including PoE Switch, PoE Midspans.

Nowadays, many newly developed PoE powered devices require higher power consumption than the standard. Meanwhile some powered devices require high initial current to boot. After the self-test, the required current is within IEEE802.3af standard. To solve this problem, many PoE device manufacturers developed high power PSE power supply.

When considering PSE power supply, users ought to choose the PSE power supply which can provide power slightly larger than the power consumption of powered device (e.g IP camera). If you decide to use multi-port PSE, ensuring each of port can output sufficient power to powered devices. Additionally, it's recommended to leave redundancy of power for ensuring the stability of PSE.