IBM DCS9550 1S1 - Manual (Page 18)

Introduction
IBM System Storage DCS9550 1S1 Storage Expansion Unit Installation, Service, and User Guide 3
1.2 The Plug-in Modules
An DCS9550 1S1 Storage Expansion Unit requires one or more of the following modules for normal operation:
1.2.1 Power Supply/Cooling Module
Two auto ranging AC 450WPower Supply/Cooling modules ( Figure 1–4 ) are supplied mounted in the rear of the
enclosure as part of the subsystem core product.
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PSU voltage operating ranges are nominally 115V or 230V AC, selected automatically.
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Four LEDs mounted on the front panel of the Power Supply/Cooling module (see Figure 2–1 ) indicate the status
of the PSU and the fans.
1.2.1.1 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.
Figure 1–4 AC Power Supply/Cooling Module