Product manual

36 Barracuda 2LP Product Manual, Rev. D
7.3 Heat/power dissipation
The heat and power dissipation values for your drive are listed below.
ST31250 ST31250
N/W/WC ND/WD/DC
Typical seek and read power dissipation* 11W 12W
(35 BTUs/hr) (41 BTUs/hr)
Typical power dissipation under 9W 9W
idle conditions (31 BTU/hr) (31 BTUs/hr)
ST32550 ST32550ND
N/W/WC ND/WD/DC
Typical seek and read power dissipation* 11W 12W
(35 BTUs/hr) (41 BTUs/hr)
Typical power dissipation under 9W 9W
idle conditions (31 BTUs/hr) (31 BTUs/hr)
*DC power average at nominal voltages
7.4 Environmental limits
Temperature and humidity must not cause condensation within the drive.
Altitude and atmospheric pressure specifications are referenced to a
standard day at 58.7°F (14.8°C). Maximum wet bulb temperature is 82°F
(28°C).
7.4.1 Temperature
a. Operating
The MTBF specification for the drive is based on operating at a local
ambient temperature of 95°F (35°C). Occasional excursions to drive
ambient temperatures of 122°F (50°C) may occur without impact to
specified MTBF. The enclosure for the drive should be designed such that
the temperatures at the locations specified in Section 6.2.2 are not
exceeded. Air flow may be needed to achieve these temperatures.
Continual or sustained operation at case temperatures above these
values may degrade MTBF.
The drive meets all specifications within a 41° to 122°F (5° to 50°C)
drive ambient temperature range with a maximum gradient of
36°F (20°C) per hour.
b. Non-operating
Non-operating temperature should remain between –40° to 158°F (–40°
to 70°C) package ambient with a maximum gradient of 36°F (20°C)
per hour. This assumes that the drive is packaged in the shipping
container designed by Seagate.
7.4.2 Relative humidity
The values below assume that no condensation on the drive occurs.
a. Operating
5% to 95% relative humidity with a maximum gradient of 10% per hour
b. Non-operating
5% to 95% relative humidity