Customers need to correctly identify a 'U-space' or 'rack space.'
All versions and serial ranges.
Incorrect placement of equipment can create airflow problems, like hot air recirculation.
Resolution: see below
As set forth by the EIA/ECA-310-E Standard:
1. For any Rackmount device or enclosure - a U or unit of rack space is equivalent to 1.75 inches or 44.45 mm.
2. The mounting hole pattern on a rack or enclosure must follow the following guideline:
- Vertical Hole spacing must follow a pattern of 5/8""-5/8""-1/2"" or 15.9mm-15.9mm-12.7mm
- Horizontal Hole spacing must be 18.3"" or 465 mm (+/- 1.6 mm)
- Clearance between inner edges of mounting rails must be 450 mm at minimum
- Outside edges of mounting rail must be 483.4 mm apart at minimum
EIA/ECA-310-E rail specifications in attached file.
To properly mount a device in the rack, a user needs to utilize the notched
square mounting hole to indicate the center of a U space. For Example, to mount a 1 U device, 3 mounting holes would be covered by the device with the notched hole residing in the center of the group of 3. Mounting in an "off-U position", effectively moving the installed device 1 hole space up or down is incorrect and will lead to airflow and cooling issues.