SharkRack 45U - Manual (Page 37)

SharkRack Enclosure Installation Guide
ID-00210-000 REV D, ECO2773 Page 37 of 46
Appendix A: Glossary
EIA:
For more than 72 years the Electronic Industries Alliance has been the national trade
organization representing U.S. electronics manufacturers. Committed to the competitiveness of
the American producer, EIA represents the entire spectrum of companies involved in the design
and manufacture of electronic components, parts, systems and equipment for communications,
industrial, government and consumer uses.
U (or RU):
A Rack Unit, or sometimes referred to as “U”, is the measure of space in a rack cabinet
enclosure equal to 1.75 inches as defined by the EIA-310 standard. Each Rack Unit in an EIA
rack cabinet enclosure will have three holes. The first hole is spaced at .25 inches from the
bottom of the U to the center, followed by 2 holes spaced at .625 center to center and then .25
inches to the top of the RU.
Figure 39
“U” Spacing
Zero U:
Zero U is any rack unit that is not a part of the main stacked rack unit in a cabinet.