Power requirements

To get the best PoE performance, you should provide enough PoE power to exceed the maximum amount of power that is needed by all the PDs that are being used.

By connecting an external power supply you can optionally provision more PoE wattage per port and or supply the switch with redundant 12V power to operate should an internal power supply fail.

By installing a second power supply in the 5406zl or a third power supply in a 5412zl chassis, depending on how many PoE ports are being supplied with power, the switch can have redundant power if one power supply fails. A Power Supply Shelf (external power supply) can also be connected to the 5400zl switches to provide extra or redundant PoE power.

For example, if the 5406zl has two 24-port PoE modules (J8702A) installed, and all ports are using 15.4 watts, then the total wattage used is 739.2 watts (48 x 15.4.) To supply the necessary PoE wattage a J8713A power supply is installed in one of the power supply slots.

To gain redundant power, a second J8713A must be installed in the second power supply slot. If the first power supply fails, then the second power supply can supply all necessary power.

See the PoE planning and implementation guide for detailed information about the PoE/PoE+ power requirements.