16 | ST12450W/WD Installation Guide, Rev. B |
2A –10% tolerance is permissible during initial start of the spindle but must return to ±5% before reaching 7,200 RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been completed and that the drive is able to accept selection by the host initiator.
3See the +12V current profile in the Barracuda 2, 2HP Product Manual (publication number 83328900).
4This condition occurs when the Motor Start option is en- abled and the drive has not yet received a Start Motor command.
5See “Conducted noise immunity” in the Barracuda 2, 2HP Product Manual. The specified voltage tolerance is inclu- sive of ripple, noise, and transient response.
6At power-up, the motor current regulator limits the +12V current to an average value of less than 2.0A, although instantaneous peaks may exceed this value. These peaks should measure 5 msec duration or less.
7Minimum current loading for each supply voltage is not less than 3% of the maximum operating current shown.
8Use separate ground returns for +5 and +12V supplies.
9Where power is provided to multiple drives from a common supply, carefully consider individual-drive power require- ments. Where multiple units are powered on simultaneously, be sure the peak starting current is available to each device.
10Operating condition is a third-stroke seek at OD and Read One Track. The command is issued every 0.07 seconds for ST12450WD models and every 0.075 seconds for ST12450W models.
