800-Series Fan Behavior expectations

FAQ_User — Tue, 17 Dec 2013 00:19:00 GMT

Article ID: 16026

Products
800-Series

Goals
When do the switch cooling fans run?
When might the fans be expected to toggle to high speed, low speed, or shut off?

Solution
As stated in the 800-Series Hardware Installation Guide...
Fan Operation on the 800-Series

The 800-Series switches support individually unique fan control mechanisms.

1. After turning on the 08H20G4-48, 08G20G2-08 and 08G20G4-24 switches, during
the initial boot-up procedure, the internal fans will turn on and will only
turn off when the room temperature is below 36° C (96.8° F). After the
initial boot-up, if the room temperature rises above 35° C (95° F), the
fans will turn on again and only turn off when the room temperature falls
below 33° C (91.4° F).

2. After turning on the 08G20G2-08P switch, during the initial boot-up
procedure, the internal fans will turn on and will only turn off when the
room temperature is below 34° C (94° F). After the initial boot-up, if the
room temperature rises above 33° C (91.4° F), the fans will turn on again
and only turn off when the room temperature falls below 30° C (86° F).

3. After turning on the 08H20G4-24P, 08H20G4-48P, 08G20G4-24P, 08G20G4-48,
and 08G20G4-48P switches, during the initial boot-up procedure, the
internal fans will turn on and will never turn off. After the initial
boot-up, if the room temperature rises above 35° C (95° F), the fans will
operate at high speed and when the room temperature falls below 33° C
(91.4° F), the fans will operate at low speed.

The 08H20G4-24 does not have any internal fans and can operate between 0° C
(32° F) and 50° C (122° F).To restate with further detail, this table outlines the temperature in Degrees Celsius at which a switch unit's fans - after initial boot-up - might be expected to toggle from off to low speed, off to high speed, low speed to high speed, high speed to low speed, high speed to off, or low speed to off.

The LM75 values are those detected and reported by the unit.
The Ambient values reflect the air temperature outside the unit.

Note that it often takes some time (hours) for the unit to "settle" on a temperature.
FAN OFF FAN LOW FAN HIGH
MODEL LM75 AMBIENT LM75 AMBIENT LM75 AMBIENT

08H20G4-48 <=44C <=32C >=52C >=36C
08G20G2-08 <=35C <=32C >=48C >=36C
08G20G4-24 <=47C <=32C >=66C >=36C

08G20G2-08P <=44.5C <=29C >=66C >=34C
(serial# ending 5B and lower)
08G20G2-08P <=43.5C <=29C >=58C >=34C
(serial# ending 5C and higher)

08H20G4-24P <=34C <=32C >=38C >=36C
08H20G4-48P <=36C <=32C >=44C >=36C
08G20G4-24P <=38C <=32C >=43C >=36C
08G20G4-48 <=43C <=32C >=48C >=36C
08G20G4-48P <=36C <=32C >=43C >=36C

08H20G4-24 *all temps - fanless*

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800-Series Fan Behavior expectations