# HP FlexFabric 11908-V Installation Manual: Fan Tray Power Consumption; System Power Consumption; Heat Dissipation

Flexfabric 11900 series.

Model
LSU1QGS8SF9
LSU1TGT24SF9
LSU1FAB08D9
LSU1FWCEA0

## Fan tray power consumption

The switch uses fans with the automatic speed adjustment function. The fan speed is automatically
adjusted based on the heat dissipation condition of the switch. The power consumed by a fan tray
depends on the fan speed.
Table 16 Fan tray power consumption
Model
11908-V
System power consumption
The system power consumption of the switch depends on the type and number of cards and the fan tray
power consumption.
The minimum system power consumption is the total static power consumption of all cards plus the
minimum fan tray power consumption. For example, for a 1 1908-V switch that has two LSU1SUPB9
MPUs, two LSU1TGS32SF9 LPUs, two LSU1FAB08D9 switching fabric modules, and one fan tray,
the minimum system power consumption of the switch is 2 × 45 + 2 × 126 + 2 × 101 + 13 = 557
W.
The maximum system power consumption is the total dynamic power consumption of all cards plus
the maximum fan tray power consumption. For example, for a 1 1908-V switch that has two
LSU1SUPB9 MPUs, two LSU1TGS32SF9 LPUs, two LSU1FAB08D9 switching fabric modules, and
one fan tray, the maximum system power consumption of the switch is 2 × 50 + 2 × 170 + 2 × 135
+ 329 = 1039 W.
Heat dissipation
Heat dissipation is measured in BTU/h, and 1 W equals 3.4121BTU/h.
The heat dissipation of the switch depends on its power consumption. To calculate heat dissipation of the
switch, assume 90% power consumption is converted to heat, and the efficiency of the power supply is
90%. Heat dissipation/hour of the switch is 0.9 × (total power consumption of the cards plus power
consumption of the fan tray)/0.9 × 3.4121.
For the power consumption of cards and fan trays, see
consumption."
Minimum static power consumption
100 W
103 W
101 W
109 W
Table 16
shows the power consumption of different fan trays.
Minimum fan tray power consumption
13 W
Maximum dynamic power consumption
135 W
190 W
135 W
157 W
Maximum fan tray power consumption
329 W
"Module power consumption and system power
63