3com 3C39036 User Manual

C

HAPTER

 2: I

NSTALLING

 

THE

 S

YSTEM

To find the top of the pattern, locate the midpoint 
between any two holes that are spaced 

1

/

2

 inch apart. 

Figure 2-3 shows the universal mounting hole 
pattern.

Figure 2-3   Universal Mounting Hole Pattern

Determine which holes to use to mount your system.

Two Switch 3900s are designed to mount in any 3U 
space of the rack (that is, the space occupied by three 
instances of the universal mounting hole pattern). 

Figure 2-4 illustrates the positions of two Switch 
3900s, one attached to holes 1 and 4 and the other 
attached to holes 6 and 9. 

To mount only one Switch 3900, use either position.

Figure 2-4   Placement of Switch 3900s in a Distribution Rack

Repeat the process on the other rail.

Top of the pattern
or top of the rack

Universal
mounting
hole pattern
= 1U
= 1 3/4 inches

1/2"

1/2"

1/2"

1/2"

5/8"

5/8"

5/8"

5/8"

5/8"

5/8"

1U

1U

1U

Bottom of the pattern

Hole 1

Hole 3

Hole 6

Hole 8

Placement of
Switch 3900
(position 2)

Placement of
Switch 3900
(position 1)

3U
(5.25")