Understanding Rack-Mount Vertical Units - Intergraph InterServe 90 System Setup

4
Maintain the following operating environment.
Temperature range: 50 F to 77 F (10 C to 25 C). Optimum: 70 F (21 C)
Humidity range: 20 % to 80 % non-condensing. Optimum: 50 %

Understanding Rack-Mount 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 the InterServe 90 requires
six vertical units (6 U), or 10.5 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.
Tinnerman Nut
Mounting Hole 4
Mounting Hole 3
Mounting Hole 2
Mounting Hole 1
Vertical Unit Marker