GE Industrial Solutions GPS 4812_24 - Manual (Page 74)

Galaxy Power System 4812/24
11 - 2 Maintenance and Replacement Issue 9 Januray 2008
Requirements, continued
Rectifier Fan
Assembly
The expected life of the rectifier fans at 25°C (77°F) is approximately
eight years. The fans in the rectifiers may be replaced in the field.
Two approaches can be taken to fan maintenance.
• The first approach is to replace the fan on a routine basis every
seven to eight years; this ensures that the fan does not fail in the
field under normal operating conditions. This approach is
appropriate when there are no remote alarm facilities at the site.
• The second approach, assuming one has remote alarm capability, is
to wait until the fan fails. The rectifier will safely shut down and
issue both a fail alarm and a thermal alarm. The fan can then be
replaced. Since it is likely that all the rectifiers in that installation
are of roughly the same age, all rectifier fans at that site should be
replaced at that time.
The approach used depends on the location and manning of the site as
well as the monitoring of alarms used at the site. Refer to “Replacing a
Rectifier Fan Assembly” in this section.