Seagate 146.8GB HD ST3146854LW User Manual

Cheetah 15K.4 SCSI Product Manual, Rev. B

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When mounting the drive using the bottom holes (x-y plane in Figure 15) care must be taken to ensure that the 
drive   is   not  physically  distorted  due  to   a  stiff  non-flat  mounting  surface . The  allowable  mounting  surface 
stiffness is 80 lb/in (14.0 N/mm). The following equation and paragraph define the allowable mounting surface 
stiffness:

where ‘k’ represents the mounting surface stiffness (units of lb/in or N/mm), and ‘x’ represents the out-of-plane 
mounting surface distortion (units of inches or millimeters). The out-of-plane distortion (‘x’) is determined by 
defining a plane with three of the four mounting points fixed and evaluating the out-of-plane deflection of the 
fourth mounting point when a known force (F) is applied to the fourth point.

Before mounting the drive in any kind of 3.5-inch to 5.25-inch adapter frame, verify with Seagate 
Technology that the drive can meet the shock and vibration specifications while mounted in such an 
adapter frame. Adapter frames that are available may not have a mechanical structure capable of 
mounting the drive so that it can meet the shock and vibration specifications listed in this manual.

Signal ground (PCBA) and HDA ground are connected together in the drive and cannot be separated by the 
user. The equipment in which the drive is mounted is connected directly to the HDA and PCBA with no electri-
cally isolating shock mounts. If it is desired for the system chassis to not be connected to the HDA/PCBA 
ground, the systems integrator or user must provide a nonconductive (electrically isolating) method of mount-
ing the drive in the host equipment.

Increased radiated emissions may result if you do not provide the maximum surface area ground connection 
between system ground and drive ground. This is the system designer’s and integrator’s responsibility.

k * x = F < 15lb = 67N