Enclosure Chassis - Seagate Exos AP 4U100 Installation And Maintenance Manual

Enclosure chassis

The 4U100 chassis consists of a sheet metal enclosure with integrated PCBs and a module runner system. The enclosure
is comprised of a drive channel and a controller channel, and features removable top cover lids. Enclosure top and rear
panels provide access to plug-in modules known as customer-replaceable units (CRUs). Each enclosure is comprised of
sheet steel that is bonded together using rivets, welding, and other forced contact methods. The metal surfaces are free
from non-conductive coatings and paint.
• The 4U100 chassis has a 1.2 m rack mounting that enables it to be installed onto standard 1.2 m racks, and uses
4 units of EIA rack space (i.e. 7") with the standard capacity CMA, and
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5 units of EIA rack space (i.e. 8.75") with the high capacity CMA.
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Optional lift handles on the chassis side walls facilitate hoisting and installation. See
• The Cable Management Arm (CMA) routes cables from the controller channel and external connections, and secures
them for in-rack servicing of the installed enclosure.
• An internal high-speed harness ensures routing of cables controlled to specification; protects the interfaces between
cables and connectors; and provides a connector system designed for positive (latched) mating.
• The drive channel bus-bar distributes power from the power midplane to 24 LFF drive baseplanes.
• Four baseplane PCBs support 96 LFF drive module connections in the main bay.
• One baseplane PCB supports 4 SFF drive modules in the controller bay.
• The enclosure top lid A provides access to 96 low profile LFF drive modules and HS expanders. Top lid B provides
access to 4 SFF drive modules, 2 controller channel fans, and 2 Storage personality modules. All drives are oriented
vertically, and held in a Disk Drive In Carrier (DDIC) module (the DDIC is compatible with both rotating and Solid state
drives). The DDIC supports the drive and transmits light from the bay LEDs mounted on the baseplane.
NOTE: Enclosure top lids A and B are fixed with a latch mechanism. An operator need to pull out the enclosure
on a rail to allow to access one lid at a time for a service event. See
• 2 removable, hot-swap expander cards connect through a fixed mount bracket and link card to each of the 24 LFF
drive module baseplanes (8 hot-swap expander cards total), providing a dual-path High Availability (HA) connection
to the drives plugged into the baseplane.
• Within the controller channel compartment, controller channel fans provide additional cooling for the controller
channel bay.
• Within the rear panel, the chassis assembly can hold a maximum of two PSUs, four system fans, two Controller
modules, and the flattened cable coils held by the bracket assembly on the CMA shelf (atop system fan sheet metal).
IMPORTANT: A Controller module service blank must be installed after its removal during servicing. This configuration is
required to ensure minimum air loss and sufficient cooling through the enclosure during operation.
Each Controller module should be replaced within 45 seconds of its removal, OR the controller service blank should be inserted
within 45 seconds to permit servicing of the removed controller without replacing it.
Figure 30 (page
Figure 10 (page 27).
Enclosure chassis
51).
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