Cisco Systems 8240 Manual De Usuario

The MGX 8240 incorporates three fan trays. Each fan tray:

Is a self-contained card installed from the front of the shelf.

Contains three fans.

Is hot-swappable for ease of servicing.

Has a bi-colored LED to show Ready (green) and Fault (red).

Any two of the three fan trays are sufficient to cool a fully-loaded chassis. Each fan has a tachometer
output. These nine outputs are bused to each of the 15 PSM card slots.

During configuration, the installer should configure at least one PSM card to monitor and report fan
status. All other PSM cards have this feature disabled as the default.

Upon detection of any fan failure, the PSM performs the following:

Sets a major alarm.

Sets the fan tray LED state to Fault on the fan tray containing the failed fan.

If a fan tray fails, leave it in place until a replacement unit is available. The chassis can runo
n two fan trays, but when a fan tray is removed, all three fans on the tray appear to fail. This
condition generates fan failure alarms.

The shelf is equipped with a removable reusable air filter. Air intake is from the front and from the sides
to maximize the intake air volume. Figure 2-4 represents the front and side air intakes.