English: An egg-type porcelain strain insulator, sometimes called a "Johnny ball". These are used in guy cables supporting utility poles, to prevent any high voltage on the cable due to leakage currents or an electrical fault on the pole from reaching the lower part of the cable which is accessible by the public. They are also used in guys supporting radio antenna masts. This design has two mechanical advantages. The ceramic is under compression rather than tension, which takes advantage of ceramic's greater compressional strength; and if the ceramic breaks the two wire loops are still linked and will not part.
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