IBM DCS9550 1S1 - Manual (Page 34)

Installation
IBM System Storage DCS9550 1S1 Storage Expansion Unit Installation, Service, and User Guide 19
Important Install the Power Supply/Cooling module (PSU 0) in the bay on the right
side (Rear Bay 1) of the enclosure in an “upside down” orientation. If
necessary, reorient the power cord clip so that the power cord can be
properly retained.
3 Cam the module home by manually closing the PSU handle (Figure 2–4). You should hear a
click as the handle latches engage.
4 Connect the power supply cord to the power source and switch the power supply ON.
Figure 2–2 AC Power Supply/Cooling Module - Handle in Open Position
Figure 2–3 Installing an AC Power Supply Cooling Module (1)