The HP ProCurve Switch 4000M/8000M Power Supply (HP J4119A) is a redundant power supply that you can add to an HP ProCurve Switch 4000M and 8000M to provide additional switch reliability.

Features: The HP ProCurve Switch 4000M/8000M Power Supply is identical to the power unit that is preinstalled in the HP ProCurve Switch 4000M and 8000M, and has the following features:

• power load sharing—with two supplies installed, they share the power load, which increases the life of both of the power supplies.
• provides power redundancy—if either one of the power supplies should fail, the remaining supply provides enough power to continue running a fully loaded Switch 4000M or 8000M.
• “hot swap” operation—you can add or replace either Power Supply without having to shut down or reboot the switch.
• automatic fault detection—if the power supply encounters a problem, the Switch 4000M and 8000M can immediately detect the condition and report it via the Power status and Fault LEDs on the switch. Event messages will also be displayed in the switch console event log and the web browser interface Alert log.