Understanding Vertical Units; Installing The Base Unit - Intergraph StudioZ GT RAX Setup Manual

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Understanding Vertical Units

You can identify a vertical unit (U) mark as a round hole along the edge of the side rails. Note that
it is smaller than the mounting holes used to secure equipment in a rack. The 40 U rack
additionally uses a square hole to indicate every fourth vertical unit. You should determine the
vertical mounting space within a rack enclosure for each device you wish to install. For example,
an AC distribution box can require 1 U or 2 U of mounting space, while a server requires five
vertical units (5 U), or 8.75 inches, of mounting space.
A vertical unit equals 1.75 inches and consists of three mounting holes.
The mounting hole diameter is 7.1 mm (industry standard).
Mounting holes are counted upward after locating the first mounting hole within the range of
vertical units required to install the equipment.
The following figure shows installing a tinnerman nut to mounting hole 3 of a vertical unit.

Installing the Base Unit

CAUTION Two persons are required to perform the following procedures.
To install the base unit:
1. Remove the system base unit and mounting rails from the carton and shipping materials. Use
a helper!
Mounting Hole 4
Mounting Hole 3
Tinnerman Nut
Mounting Hole 2
Mounting Hole 1
Vertical Unit Marker