Hardware Installation and Reference Guide    Appendix 
86 
7.5  Cabling 
When the switch is installed in a standard 19-inch rack, secure the cables around the cable management brackets. Top cabling or 
bottom cabling is adopted according to the actual situation in the equipment room. All transferred cable connectors should be placed 
at the bottom of the rack in an orderly manner instead of outside the rack that is easy to touch. Power cords are routed beside the 
rack, and top cabling or bottom cabling is adopted according to the actual situation in the equipment room, such as the positions of 
the DC power distribution box, AC socket, or lightning protection box. 
Requirements for Cable Bend Radius 
  The bend radius of a fixed power cord,  Ethernet cable, or flat cable should be over five  times greater than their respective 
diameters.  The  bend  radius  of  these  cables  that  are often  bent  or  plugged  should  be  over  seven  times  greater  than  their 
respective diameters. 
  The bend radius of a fixed common coaxial cable should be over seven times greater than its diameter. The bend radius of the 
common coaxial cable that is often bent or plugged should be over 10 times greater than its diameter. 
  The bend radius of a fixed high-speed cable (such as SFP+ cable) should be over five times greater than its diameter. The bend 
radius of the fixed high-speed cable that is often bent or plugged should be over10 times greater than its diameter. 
Requirements for Fiber Bend Radius 
  The diameter of a fiber tray to hold fibers should be over 25 times greater than the diameter of the fiber. 
  When an optical fiber is moved, the bend radius of the fiber should be over 20 times greater than the diameter of the fiber. 
  During cabling of an optical fiber, the bend radius of the fiber should be over 10 times greater than the diameter of the fiber. 
Precautions for Bundling up Cables 
  Before cables are bundled, mark labels and stick the labels to cables wherever appropriate. 
  Cables should be neatly and properly bundled in the rack without twisting or bending. 
Figure 7-6 Binding Cables (1) 
 
  Cables of different types (such as power cords, signal cables, and ground cables) should be separated in cabling and bundling. 
Mixed bundling is disallowed. When they are close to each other, it is recommended to adopt crossover cabling. In the case of 
parallel cabling, maintain a minimum distance of 30 mm (1.18 in.) between power cords and signal cables. 
  The cable management brackets and cabling troughs inside and outside the rack should be smooth without sharp corners.