User guide

EVA cabinet measures and tolerances
EVA component rack mount brackets are designed to fit cabinets with mounting rails set at depths
from 27.5 inches to 29.6 inches, inside rails to inside rails.
Weights, dimensions and component CG measurements
Cabinet CG dimensions are reported as measured from the inside bottom of the cabinet (Z), the
leading edge of the vertical mounting rails (Y), and the centerline of the cabinet mounting space (X).
Component CG measurements are measured from the bottom of the U space the component is to
occupy (Z), the mounting surface of the mounting flanges (Y), and the centerline of the component
(X).
Determining the CG of a configuration may be necessary for safety considerations. CG considerations
for CG calculations do not include cables, PDU’s and other peripheral components. Some consideration
should be made to allow for some margin of safety when estimating configuration CG.
Estimating the configuration CG requires measuring the CG of the cabinet the product will be installed
in. Use the following formula:
d
component
W = d
system cg
W
where d
component
= the distance of interest and W = Weight
The distance of a component is its CG’s distance from the inside base of the cabinet. For example,
if a loaded disk enclosure is to be installed into the cabinet with its bottom at 10U, the distance for
the enclosure would be (10*1.75)+2.7 inches.
Airflow and Recirculation
Component Airflow Requirements
Component airflow must be directed from the front of the cabinet to the rear. Components vented to
discharge airflow from the sides must discharge to the rear of the cabinet.
Rack Airflow Requirements
The following requirements must be met to ensure adequate airflow and to prevent damage to the
equipment:
• If the rack includes closing front and rear doors, allow 830 square inches (5,350 sq cm) of hole
evenly distributed from top to bottom to permit adequate airflow (equivalent to the required 64
percent open area for ventilation).
• For side vented components, the clearance between the installed rack component and the side
panels of the rack must be a minimum of 2.75 inches (7 cm).
• Always use blanking panels to fill all empty front panel U-spaces in the rack. This ensures proper
airflow. Using a rack without blanking panels results in improper cooling that can lead to thermal
damage.
Non-standard rack specifications106