Howard Small Power - Manual (Page 6)

Document 2.4.54 Revision 0
July 2006 Small Power Substation Transformers
6
STORAGE
Transformer Storage
Transformers can be stored if properly prepared. It is
recommended that stored transformers be completely
assembled. Prior to storage, transformers should be
pressure tested according to the instructions on page 9
(Pre-energization Tests and Checklist) . The gas space
above the insulating fluid should be pressurized with
dry nitrogen to a pressure between two and three PSIG.
This will prevent a negative internal pressure which
might draw moisture into the tank. Transformers not
designed for outdoor use must be stored indoors. If
the transformer is not completely assembled, separate
components and accessories should be stored in a
clean dry area in their original shipping containers.
Extended Storage
If the transformer is to be stored for an extended period
of time before being placed into service, it should be
placed on a firm level surface.
All space heaters (if supplied) in terminal chambers,
switch cabinets, control cabinets or other enclosures,
must be connected and energized at all times to control
moisture. If it is not practical to energize the control
cabinet space heater, desiccant packets may be used
to control moisture in control cabinets only. Desiccant
packets must be replaced periodically to maintain
effectiveness.
It is recommended that the transformer be inspected
periodically as described below while it is in extended
storage. Results should be recorded and compared
with previous results to ensure that no damage or
change in condition has occurred.