Fan and Acoustic Noise
Table 21: Fan and Acoustic Noise
Switch Model
Bystander Sound Pressure (at 25°C)
Declared Sound Power (at 25°C)
VSP7400-32C-AC-F
(FB airflow)
45 db(A)
6.5 bels
VSP7400-32C-AC-R
(BF airflow)
47 db(A)
6.7 bels
VSP7400-48Y-8C-F
(FB airflow)
52.2 db(A)
6.8 bels
VSP7400-48Y-8C-R
(BF airflow)
50.5 db(A)
6.7 bels
Fan Tray and Speed Variation
Fan speeds are adjusted based on calculations of the temperatures on all sensors. Due to one fan being
located behind the other, air pushed from one fan may cause the other fan in the module to run at a
higher speed. One fan can run at medium speed while the other can spin at high speed if one is close to
the temperature boundary.
Table 22: Fan Tray Speed Variation
Description
Operation Status
Operation Speed
Airflow Direction
Tray 1 Fan 1
up
high speed
Unknown*
Tray 1 Fan 2
up
medium speed
Unknown*
Tray 2 Fan 1
up
high speed
Unknown*
Tray 2 Fan 2
up
medium speed
Unknown*
Tray 3 Fan 1
up
high speed
Unknown*
Tray 3 Fan 2
up
medium speed
Unknown*
Tray 4 Fan 1
up
high speed
Unknown*
Tray 4 Fan 2
up
medium speed
Unknown*
Tray 5 Fan 1
up
high speed
Unknown*
Tray 5 Fan 2
up
medium speed
Unknown*
Tray 6 Fan 1
up
high speed
Unknown*
Tray 6 Fan 2
up
medium speed
Unknown*
* - The color of the tab on the fan tray indicates the airflow direction:
•
Red = Front-to-Back
•
Blue = Back-to-Front
Technical Specifications
VSP 7400 Series Switches: Hardware Installation Guide
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