Appliance-induced shut down
The terms "protection" or "protected" refer to a power supply that has shut down or locked up. The appliance may turn off to protect itself and other components that are connected to the appliance. A short-circuit, voltage overload, or power surge can cause self-protection.
If both power supplies are faulty, do not attempt to turn on the appliance. If the power supplies stop working, the fans in the power supplies do not operate to cool the appliance. Physical damage to the appliance and a potential loss of data can occur due to increased temperatures.
Refer to the NetBackup 52xx and 5330 Appliance Troubleshooting Guide for more information, at the following site.