
104 SEBU8088-06
Maintenance Section
Generator - Inspect
Drying Methods
The following m
ethods can be used for drying a
generator:
•
Self-circulat
ing air method
•
Oven method
NOTICE
Do not allow th
e winding temperature to exceed 85 °C
(185.0 °F). Temperatures that are greater than 85 °C
(185.0 °F) will damage the winding insulation.
Self-Circulating Air Method
Run the engine
and disconnect the generator load.
This will help circulate air. Operate the generator
space heaters.
Oven Method
Place the ent
ire generator inside a forced air drying
oven for four hours at 65 °C (149 °F).
NOTICE
Use a forced a
ir type oven rather than a radiant type
oven.
Radiant type
ovens can cause localized overheating.
i01461264
Generator - I
nspect
SMCS Code: 4450-040
Personal injury or death can result from improper
troublesho
oting and repair procedures.
The following troubleshooting and repair proce-
dures shoul
d only be performed by qualified per-
sonnel familiar with this equipment.
Refer to Saf
ety Section, “Generator Isolating for
Maintenance” for information regarding the procedure
to safely isolate the generator.
Proper mainten
ance of electrical equipment requires
periodic visual examination of the generator and
periodic visual examination of the windings. Proper
maintenance o
f electrical equipment also requires
appropriate electrical checks and appropriate thermal
checks. Insulation material should be examined for
cracks. The i
nsulation material should be examined
for accumulations of dirt and dust. If there is an
insulation resistance value that is below normal, a
conductive
path may be present. This conductive
path may be made of one of the following materials:
•
Carbon
•
Salt
•
Metal dust
•
Dirt that is
saturatedwithmoisture
These contaminants will develop a conductive path
which may pr
oduce shorts. Cleaning is advisable if
heavy accumulations of dirt can be seen or if heavy
accumulations of dust can be seen. If excess dirt is
the cause o
f a restriction in the ventilation, cleaning
is also advisable. Restricted ventilation will cause
excessive heating.
NOTICE
To avoid the possibility of deterioration to the genera-
tor windings, do not clean the generator unless there
is visual,
electrical, or thermal evidence that dirt is
present.
If harmful dirt accumulations are present, a variety
of cleaning techniques are available. The cleaning
procedure that is used may be determined by one of
the items on the following list:
•
The extent of the cleaning procedure that is being
attempted
•
The type of enclosure of the generator
•
The voltage rating of the generator
•
The type of dirt that is being removed
Cleaning (Assembled Generators)
Cleaning may be required at the point of installation.
At this point, complete disassembly of the generator
may not be necessary or feasible. In this case,
a vacuum cleaner should be used to pick up the
following items: dry dirt, dust, and carbon. This will
prevent the spreading of these contaminants.