Alcatel-Lucent 7705 - Page 50

7705 SAR-8 Overview
Page 50 7705 SAR-8 Installation Guide
The 7705 SAR-8 supports three variants of the fan module:
• –48 VDC variant, which does not support an extended temperature range
(version 1 – introduced in Release 1.0)
• –48 VDC variant, which supports an extended temperature range
(version 2 – introduced in Release 2.0)
• +24 VDC variant, which supports an extended temperature range
(version 2 – introduced in Release 2.0)
Fan Operation
The Fan module houses eight fans. Air enters from the intake vent on the right side of the
chassis and exits through the exhaust vent on the left side. The fans have one operating speed
(full speed). The fans on the –48 VDC variant (version 1), are always on. The fans on the
extended temperature –48 VDC variant and on the +24 VDC variant (version 2) are either all
on or all off, depending on the temperature monitoring described below.
The FAN LED on the Fan module provides the following indications:
• green: normal operation
• amber: fans have turned off due to a low temperature or a fan has failed (the
7705 SAR software can detect which situation has occurred and will raise an alarm
if a fan failure exists)
• unlit: fan power failure
Note: The –48 VDC and +24 VDC variants of the fan module (version 2) introduced in
Release 2.0 are not compatible with previous software releases of the 7705 SAR.
Warning: Individual fans are not field-replaceable. If a Fan Fail alarm is raised, replace the
Fan module as soon as possible. If a second Fan Fail alarm is raised, the Fan module must
be replaced immediately.