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Electrical porcelain is
an ideal insulator because not only does it have desirable
electrical properties, but even more important, it maintains these
properties through out its entire life unlike polymers. Porcelain is
proven to be superior to polymers as it is resistant to Ultra
Violet, environmental, and chemical
degradation.
An important
characteristic of any insulation, particularly for switched and
circuit-interrupting devices, is its ability to withstand arcing. An
electric arc can destroy insulation by actually breaking down the
insulation resistance thus causing the insulator to become conducting, or
its heat may be sufficient to cause the insulator to fracture.
Electrical porcelain
does neither! It withstands arcing without injury and, because
of its extremely high softening temperature and resistance to thermal
shock, it is practically indestructible by an electric arc.
The high dielectric
strength of electrical porcelain, coupled with physical stiffness,
permits the design and production of insulators of convenient size.
In addition to its
insulating qualities, electrical porcelain is strong mechanically
and it can be incorporated satisfactorily in almost any electrical device
by sound engineering planning at design stage.
Electrical porcelain is
extremely strong in compression. Compressive strengths ranging as
high as 40,000 pounds per square inch are not unusual. This high
compressive strength with practically zero cold flow assures dimensional
stability which is accented further by its rigidity. Thus the problem of
insulator deformation under actual service conditions, even at elevated
temperatures, is eliminated by the use of porcelain.
Electrical porcelain is versatile in
the true sense of the word...by property...by size...by
application. There are limitless thousands of sizes, shaped and
configurations you can design into your product. Whether used as
electrical insulation or as a mechanical engineering material, electrical
porcelain offers you more versatility as well as greater adaptability
and economy.
Electrical porcelain is chemically
inert. This property is all-important, since it determines
whether a material will corrode, disintegrate, char, burn, and resist
acids. The various inert ingredients used in porcelain lose their
individuality in the fusing process to form a homogeneous compound of
entirely new properties. The result is a material that offers you durability,
permanency, and practical indestructibility.
Standard commercial
tolerances of electrical porcelain are +/-0.015" per inch on the
dimensions of one inch or more, but not less than +/-0.015", except
that consideration should be given to more liberal tolerances for those
dimensions affected by the pressing operation. Tolerances are too often
established without giving consideration to each individual dimension and
the effect of its tolerance on the performance of the end product.
Therefore, it is extremely important for you as a designer or buyer of
electrical porcelain to consider tolerances from the standpoint of what
you require to produce a satisfactory product.
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