Dell PowerEdge 2650 - Page 9

2-Post Rack Installation 1-5
Universal-Hole Spacing Racks
Industry-standard two-post racks with universal-hole spacing have an alternating pattern of
three holes per U with center-to-center hole spacing (beginning at the top hole of a 1-U
space) of 15.9 mm, 15.9 mm, and 12.7 mm (0.625 inch, 0.625 inch, and 0.5 inch) for the
front and back vertical column of holes (see Figure 1-2).
Figure 1-2. Two-Post, Open-Frame Relay Rack Universal-Hole Spacing
Wide-Hole Spacing Racks
Some two-post racks with wide-hole spacing have an alternating pattern of two holes per U
with center-to-center hole spacing (beginning at the top hole of a 1-U space) of 31.7 mm
and 12.7 mm (1.25 inches and 0.5 inch) for the front and back vertical column of holes (see
Figure 1-3).
Figure 1-3. Two-Post, Open-Frame Relay Rack Wide-Hole Spacing
44 mm (1.75 inches) (1 U)
15.9 mm (0.625 inch)
12.7 mm (0.5 inch)
15.9 mm (0.625 inch)
15.9 mm (0.625 inch)
44 mm (1.75 inches) (1 U)
12.7 mm (0.5 inch)
31.7 mm (1.25 inches)