Dell PowerEdge 1850 - Manual (Page 19)

Rack Installation Guide
1-17
2 Installing the mounting rails in the rack
•
Center-mount installation
• Flush-mount installation
3 Installing the system in the rack
4 Routing cables
Marking the Rack
You must allow 1 U (44 mm, or 1.75 inch) of vertical space for each system that you install in
the two-post rack.
Universal-Hole Spacing Racks
Racks with universal-hole spacing have an alternating pattern of three holes per rack unit 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 1-10).
Figure 1-10. Two-Post, Open-Frame Relay Rack Universal-Hole Spacing
Wide-Hole Spacing Racks
Racks with wide-hole spacing have an alternating pattern of two holes per rack unit 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 columns of holes (see Figure 1-11).
12.7 mm (0.5 inch)
15.9 mm (0.625 inch)
15.9 mm (0.625 inch)
1 U (44 mm or 1.75 inches)