1.2 The Plug-in Modules
An DCS9550 1S1 Storage Expansion Unit requires one or more of the following modules for normal operation:
Power Supply/Cooling Module
Two auto ranging AC 450WPower Supply/Cooling modules
1–4) are supplied mounted in the rear of the
enclosure as part of the subsystem core product.
AC Power Supply/Cooling Module
PSU voltage operating ranges are nominally 115V or 230V AC, selected automatically.
Four LEDs mounted on the front panel of the Power Supply/Cooling module (see
2–1) indicate the status
of the PSU and the fans.
Multiple Power Supply/Cooling Modules
The DCS9550 1S1 Storage Expansion Unit must always be operated with two Power Supply/Cooling modules
fitted. The two Power Supply/Cooling modules operate together so that if one fails the other maintains the power
supply and cooling while you replace the faulty unit.
Module replacement should only take a few minutes to perform but must be completed within 10 minutes from
removal of the failed module.
IBM System Storage DCS9550 1S1 Storage Expansion Unit Installation, Service, and User Guide