GE Industrial Solutions GPS 4848_100 Users Guide (single rectifier shelf) - Manual (Page 66)

Galaxy Power System 4848/100 with 595 Series Rectifiers S1:3 and later
11 - 2 Maintenance and Replacement Issue 10 February 2008
Requirements, continued
Rectifier With the exception of a fan failure, rectifiers are repaired by
replacement.
Refer to “Installing or Replacing a Rectifier” and “Removing a
Rectifier” in this section.
Vacant Rectifier
Positions
Vacant rectifier positions in a cabinet below the top installed rectifier
may cause excessive temperature in the remaining rectifiers. If a
rectifier below the top rectifier is removed, it must be replaced
immediately or the vacated position must be occupied by a Rectifier
Shelf Cover (848680211).
If a spare rectifier or Rectifier Shelf Cover is not available, a rectifier
from the top position must be relocated to occupy the vacant position.
Rectifier Fan
Assembly
The expected life of the rectifier fans at 25°C (77°F) is approximately
seven 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 fans on a routine basis every six
to seven years; this ensures that the fans do 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 fans fail. The rectifier will safely shut down and
issue both a fail alarm and a thermal alarm. The fans 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 the Rectifier Fan Assemblies” in this section.