WARNING
cleaning agent or process that will clean all parts.
A cleaning agent that will clean one set of parts
When using cleaning solvents, avoid
may not clean another. The cleaning agent may
not be usable because it attacks the alloys or metal
burning the skin or inhaling the fumes. Use
making up the part. Therefore, different cleaning
solvents in a well-ventilated room only.
agents are necessary. The selection of these agents
will vary for different surfaces and equipment.
Test the solvent on a portion of the
You should refer to the following manuals for
component. This ensures that it will not
information on cleaning agents and their use:
destroy, blister, or otherwise damage the
material.
Aircraft Weapons Systems Cleaning and Corro-
sion Control, NAVAIR 01-1A-509, and Avionic
DO NOT use on oxygen equipment--the
Cleaning and Corrosion Prevention/Control,
inhibiting agent is flammable.
NAVAIR 16-1-540.
In addition to approved dry-cleaning solvents,
DO NOT use on hot equipment--
you can use trichlorethylene and inhibited methyl
accelerated evaporation will increase the
chloroform to clean electrical and electronic
toxic hazard.
equipment. Inhibited methyl chloroform (tri-
chlorethane) does present hazards to personnel
There are a variety of reasons for generator
and insulation. For information on such hazards,
failures or apparent failures. Before removing a
refer to NAVSHIPs' Technical Manual, chap-
generator that isn't delivering its rated voltage or
ter 9600.
current, determine that the trouble is not a
Insulation can be affected by methyl chloro-
problem in the control, feeder, or regulating
form. Insulation exposed to methyl chloroform
circuits. You should refer to the applicable
deteriorates proportionally with the time of
overhaul instruction manuals as a guide in
exposure to the solvent. After a 5-minute
determining exact voltage and frequency tolerance
during these tests.
exposure, methyl chloroform noticeably softens
varnishes and reduces dielectric strength and
Periodic inspection of generators includes the
abrasion resistance. A continuous immersion of
following:
1 hour completely destroys the properties of
most insulating materials and varnishes used in
armatures, field coils, and similarly constructed
Check for defects in the mounting flange.
If you find defects, remove and replace the
electrical components. Glass melamine and
generator. Inspect mounting studs, nuts, and
laminated phenolics, however, are only slightly
safety wire for security.
affected by such immersion.
Methyl chloroform itself is nonflammable, but
Check removable units such as ventilation
after 90 percent evaporation, the residue contains
tube, air blast cover, brush inspection band,
a high percentage of the flammable inhibitor.
terminal box, end shield, and conduit for tightness
When the solvent evaporates from containers, you
and general mechanical condition. Repair any
must recognize the flammability of the residue.
minor dents. Replace any parts with cracks.
Some of the special precautions you should
observe when using methyl chloroform include the
Check the generator and cable connections
for overheating. Discoloration and a burnt odor
following:
show overheating. Clean or replace the metal
parts. Repair or replace damaged cables.
Avoid prolonged or repeated breathing of
vapor or contact with the skin. Do not take
If you find defects you cannot repair with
internally.
the generator installed, remove it for re-
Prevent contact with open flame, as this
pair or overhaul.
may form highly toxic phosgene.
The maintenance and testing techniques used
to maintain ac generators apply to dc generators.
Immerse electrical equipment less than 5
For detailed instructions on a specific generator,
minutes, as prolonged immersion destroys
refer to the applicable manuals that are provided
most insulating materials.
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