Before You Begin; Understanding Vertical Units - Intergraph Zx10 5U System Manual

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Before You Begin

Before mounting the base unit in an equipment rack in use at your site, prevent the rack from
moving by engaging its stabilizers. If the rack is not equipped with stabilizers, refer to the rack
documentation for stabilizing instructions.
Observe the following safety precautions when mounting the base unit in a rack in use at your site
or when using the rack-mounted system:
Extend only one slide rail set at a time. Push an extended slide rail set back into the rack
before extending another.
WARNING Extending more than one slide rail set could cause the rack to fall forward,
causing damage to equipment and injury to anyone in front of the rack.
Do not push on or lean against the rack. Always engage the stabilizers. The adjustable feet
should be lowered securely against the floor.
If the rack contains an AC distribution box or an uninterruptible power supply (UPS), do not
connect its the power cord to the wall outlet until instructed to do.
Set up the system completely before you start it.
WARNING Do not move the rack with equipment mounted or powered on, or damage to
internal components may occur. Shut down the system, unplug the system
power cords from their AC power outlets, remove all equipment, and then move
the rack.

Understanding Vertical Units

A vertical unit (U) is an industry-standard measurement for rack-mounted equipment. Small
markers on the rack mounting rails usually indicate each vertical unit. For more information, see
the documentation for the racks in use at your site.
You should determine the vertical mounting space within a rack enclosure taken up by each device
you want to install. For example, an AC distribution box may require 1U or 2U of mounting
space, while the system's base unit requires 5U of mounting space.
Note the following about vertical units:
A vertical unit (U) equals 1.75 in (4.45 cm) 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.