Rack Cases 101
What is Fragility Rating?
- Fragility is measured in “G” units
- One G unit is the measure of the force exerted on a body by the Earth’s gravitational pull. This is called G Force
- Example: Twenty G units is 20 x the amount of force that the normal gravity of Earth puts on a body. If equipment is damaged just over these conditions, it has 20 G fragility
- The higher the G force needed to damage an object, the less protection is needed from shock and vibration
- Standard configurations of cases are available to protect equipment from 15-120+ G fragility
Know Your Equipment’s Weight
- Know the weight of the equipment and accessories to be mounted in the frame
- Weight and size of the equipment can quickly determine what cases can be used for the application
- Rack case configurations are available for weights from 20-340 lbs
- Custom solutions can be created for rack mountable equipment heavier than 340 lbs
Worldwide Standard Rack Unit Specification
- Internal rack heights are measured in Units or Us sometimes called Rack Units (RUs)
- One Rack Unit (1U) is equal to 1.75 inches (44.45 mm)
- Example: a 5U case has a rack that is 8.75 inches (222.25 mm) tall
- Electronics industry standard CEA-310E for vertical spacing on racks defines one U as the space taken up by three holes on the uprights of a rack (see diagram)
Three holes take up 1.25” plus .25” above and below for extra space between rack mountable components (totaling 1.75 inches)