Removing And Replacing A Fan Tray; Warnings And Notes - Alcatel-Lucent 7750 SR-a4 Installation Manual

Removing and Replacing a Fan Tray

Warnings and Notes

7750 SR-a4 and SR-a8 Installation Guide
The procedures in this section apply to the following fan trays:
• SR-a4 fan tray for the 7750 SR-a4 5-RU chassis
• SR-a8 fan tray for the 7750 SR-a8 7-RU chassis
Where figures in this section only show the fan tray that is used in the 7750 SR-a4 chassis,
the figures also apply to the 7750 SR-a8 chassis.
This section includes information about:
• Warnings and Notes on page 185
• Removing a Fan Tray on page 186
• Replacing a Fan Tray on page 187
Danger: Always keep your fingers away from rotating fan blades. Do not put your fingers
or any tool in the fan tray if the fans are still spinning. Wait until the fans stop spinning (about
2 s) before completely removing the fan tray from its slot.
Warning:
• The fan tray is hot-swappable. The 7750 SR-a chassis operates safely for up to one
minute while you replace the fan tray. If a longer maintenance time is required, power
off the system to prevent over-heating.
• In the event of a single fan failure, the remaining fans switch to their highest speeds.
The remaining fans continue to provide adequate cooling for the system, but the fan tray
must be replaced as soon as possible. Individual fans are not field replaceable.
Note: When a fan tray is replaced, the fans initially run at full speed. Thereafter, the control
system reduces the fan speed based on temperature. During normal operation, fans never
turn off completely.
Appendix C: Field-Replaceable Units
185