[Trade Journal]
Publication: Electrical Review and Western Electrician
Chicago, IL, United States
vol. 63, no. 4, p. 191, col. 2-3
A New Porcelain Strain Insulator. A new porcelain strain insulator of remarkably high strength, both mechanically and electrically, has been placed on the market by the Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa. The manufacturer recommends these insulators for use on 1,500-volt direct-current railway work and on 2,200-volt alternating-current transmission lines, a class of service for which porcelain insulators have been seldom used in the past.
It is claimed that the insulators will stand more strain than any cable used in line construction that will pass through the hole. They are of the interlinking type which makes it impossible for cables to separate even if the insulator should become shattered.
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| New Strain Insulator in Service. |
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| Several Views of Different Sizes of Strain Insulators. |
The glaze is of a dark brown color which does not attract the attention of those mischievously inclined. Sharp corners which would be apt to chip have been avoided and the shape of the grooves is such that the wires lie naturally in them. A large creepage distance is provided by the shape of the insulator, which makes it suitable for high voltages.
The smallest size of these insulators has a flashover voltage on rain test of over 13,000 volts, and the larger size, over 20,000 volts. The tensile strength of the larger size insulator is over 23,000 pounds, and its dimensions are only 5 by 4.5 by 4.5 inches.
