The power supply voltage and power of the POE switch

The power supply voltage and power of the POE switch

PoE technology is now widely used, especially the PoE switch series, whether it is webcam, wireless AP or network phone, you can see its shadow. Fengrun‘s PoE switch has been chosen by many engineers, and has been used in all walks of life. Even the Hong Rui Rui company has its own PoE switching system, which is stable in operation.

Here‘s a brief explanation of PoE‘s concepts.

Power supply voltage and power supply:

In the IEEE802.3af standard, the PSE device allows the supply of 44V~57V (standard 48V) DC voltage, the maximum current value of 350mA, so the port power up to 15.4W.

The Ethernet line allows for a resistance of 20, so the maximum effective power available on the PD is 12.95W.

Rating: different PD devices have different power range, IEEE802.3af according to different power consumption to define the PD power rating standards, PD can tell the power range of PSE, make PSE more effective power supply.

The low cost solution can be specified using the general default level (Class 0), which indicates that the maximum power required by the PD is 12.95W.

The working power range of Class 1 device is between 0.44W and 3.84W;

The working power range of Class 2 device is between 3.84W and 6.49W;

The working power range of Class 3 device is between 6.49W and 12.95W;

The Class 4 standard is reserved for the moment, and is currently the same as Class 0.

Grounding: signal detection and signal classification are conducted in low voltage mode, which is very sensitive to environmental interference. In order to prevent the error of power supply detection and classification process, the PoE equipment should be properly grounded. The grounding mode can be power ground or casing ground.

In standard three-phase AC power supplies, the protective ground is well connected to the ground. The grounding power supply device cannot be supplied, and the casing can be connected to the ground with a coarse copper wire.

Poe switch, please look for brand Hong Rui