GE GEH-5304A - Manual (Page 30)

GEH-5304A
30
FREON TF is a chlorofluorocarbon. Chlorofluorocarbons have been identified
as upper atmosphere ozone depletors. The use of Freon in industry is expected
to be greatly reduced in the future. The availability of Freon may be limited, and
its use could be prohibited by regulations.
Carbon brush performance may be ruined by absorbed solvents. Remove
brushes prior to solvent wiping.
N. Drying of Windings
Drying of machines is most effectively done by application of heat. The windings and insulation should be
heated so that their temperature does not exceed 225
°
F (125
°
C) at any location. (Do not make local hot
spots.) The machine’s own frame and the addition of some covers usually will make an effective enclosure
to contain the heat, if an oven cannot be used. Some flow of air is desirable to allow moisture to be carried
away. Methods of generating heat include blowing hot air through the machine, heating with heat lamps,
passing current through the main field coil windings, etc.
If temperatures as high as 225
°
F (125
°
C) can be attained, they should be limited to six or eight hours dura-
tion. Lower temperatures will cause correspondingly longer drying times.
Drying out can be ended when the insulation resistance to ground (corrected to 40
°
C) is restored to a satis-
factory value as described in the Insulation Resistance section. If these values do not reach a proper level,
then a thorough cleaning or complete reconditioning may be necessary.
O. Service Shop Cleaning
When the cleaning or drying methods described in preceding paragraphs do not result in restoration of ac-
ceptable insulation resistance and/or when machines are extremely dirty or contaminated, it is recommended
that the reconditioning services of a GE Service Shop be obtained. Service shops are knowledgeable and
equipped for more sophisticated restoration methods, such as hot water detergent wash, solvent and abrasive
cleaning, revarnishing and rewinding, if necessary.
P. Repair
Repairs should be made only by qualified personnel using the materials and processes for which the motor
was designed. To protect the warranty during the warranty period, all repairs must be made in a GE Service
Shop or approved repair facility. Many repairs can be easily performed with only assembly operations, if GE
replacement parts are available. If major repairs are undertaken (such as rewinding an armature), proper fa-
cilities should be used and suitable precautions observed.
When burning off old insulation materials or when welding near insulation
during rewinding, adequate ventilation must be provided to avoid exposing
personnel to noxious fumes. Combustion of exhaust fumes must be complete
and adequately vented to the outside atmosphere.
Exposure of personnel to airborne inorganic fibers must be avoided by ade-
quate ventilation or by wetting the remaining insulation components following
the burning off of the organic materials.