HP zl Power Supply Shelf: The zl Power Supply Shelf is a rack-mountable chassis with two slots for zl switch power supplies to supply additional PoE power to a zl switch.

The HP zl Power Supply Shelf provides additional Power over Ethernet (PoE) power to a zl switch beyond what can be provided by the switch's internal power supplies alone. The power supply is rack mountable and has two slots for zl switch power supplies. A large VoIP installation provides an ideal environment for the power shelf, particularly if a high level of PoE power redundancy is desired.