Dell EMC PowerEdge R740 - Cable Management Arm (CMA)

• Spacing between the front and rear mounting anges of the rack
• Type and location of any equipment mounted in the back of the rack such as power distribution units (PDUs)
• Overall depth of the rack
The static rails oer a greater adjustability range and a smaller overall mounting footprint than the sliding rails. This is because of their
reduced complexity and lack of need for CMA support.
Table 19. Rail Adjustability Range and Rail Depth
Rail
Identier
Rail Type Rail Adjustability Range (mm)* Rail Depth (mm)+
Square Round Threaded Without
CMA
With CMA
Min Max Min Max Min Max
B6 Ready Rails
Sliding
676 868 662 861 676 883 714 845
B13 Stab-in/
Drop-in
Sliding
603 915 603 915 603 915 714 845
B4 Ready Rails
Static
608 879 594 872 604 890 622 N/A
* Values represent the distance between the front and rear mounting anges on the rack
+ Measured from the front surface of the front rack mounting ange
NOTE
: For situations where CMA support is not required, the outer CMA mounting brackets can be removed from the sliding
rails to reduce the overall length of the rails and eliminate potential interferences with rear-mounted PDUs or the rack rear door.
NOTE: For the ReadyRails Sliding rails(B6) and ReadyRails Static rails (B4), the adjustment range of the rails is a function of the
type of rack in which they are being mounted. The Min/Max values listed above represent the allowable distance between the
front and rear mounting anges in the rack. Rail depth without the CMA represents the minimum depth of the rail with the outer
CMA brackets removed (if applicable) as measured from the front mounting anges of the rack.
Cable management arm (CMA)
The optional cable management arm (CMA) organizes and secures the cords and cables exiting the back of the systems. It unfolds to allow
the systems to extend out of the rack without having to detach the cables. Some key features of the CMA include:
• Large U-shaped baskets to support dense cable loads.
• Open vent pattern for optimal airow.
• Ability to be mounted on either side by simply swinging the spring-loaded brackets from one side to the other.
• Utilizes hook-and-loop straps rather than plastic tie wraps to eliminate the risk of cable damage during cycling.
• Includes a low-prole xed tray to both support and retain the CMA in its fully closed position.
• Both the CMA and the tray mount without the use of tools via simple and intuitive snap-in designs.
The CMA can be mounted to either side of the sliding rails without the use of tools or the need for conversion. However, it is recommended
that it be mounted on the side opposite to the power supplies to allow easier access to the power supplies and rear hard drives (if
applicable) for service or replacement.
Rack rails
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