Dell PowerEdge 1950 Installation Manual page 13

Figure 1-3. One Rack Unit
1 U (44 mm or 1.75 inches)
CAUTION:
If you are installing more than one system, install the mounting rails so that the first system is
installed in the lowest available position in the rack.
To mark the rack, perform the following steps:
1 Place a mark (or tape) on the rack's front vertical rails where you want to locate the bottom
of the system you are installing in the rack.
The bottom of each 1-U space is at the middle of the narrowest metal area between holes (marked
with a horizontal line on some rack cabinets—see Figure 1-4).
2 Place a mark 44 mm (1.75 inches) above the original mark you made (or count up three holes in a rack
that meets EIA-310 standards) and mark the rack's front vertical rails with a felt-tipped pen or masking
tape (if you counted holes, place a mark just above the top hole). This mark or piece of tape indicates
where the system's upper edge will be located on the vertical rails (see Figure 1-4).
12.7 mm (0.5 inch)
15.9 mm (0.625 inch)
15.9 mm (0.625 inch)
12.7 mm (0.5 inch)
Four-Post Rack Installation
11