Ceramic Insulator Identification

Different fonts and sizes of letters and numbers were used.

Ceramic insulator identification.

As technology developed insulators were needed for telephone lines electric power lines and other applications. Collecting insulators is a fun and unique hobby that will allow you to learn much about the history and make of these unique objects. There are a large variety of insulators in existence. Collectors interest has been focused on some specific areas and style numbers have been created to assist in identification and cataloging styles.

Cook porcelain insulator corp. Found on porcelain insulators. Cooper power systems the 99335 may be a catalog number. The u chart was developed by jack tod and published in 1971 porcelain insulators guide book for collectors his 3rd edition book was published in 1988.

Link to other types of insulators. Go back to main page. Jobber of electrical supplies. In the mid 1960 s a few people began collecting these glass and porcelain insulators.

Glass insulators were first produced in the 1850 s for use with telegraph lines. Today there are over 2000 collectors and insulator clubs national shows and good reference books are available. 2 vintage brown ceramic porcelain insulators locke thomas. Return to the national insulator association page.

Circa early 1920 s to circa 1930 cooke wilson e. Similar to their glass counterparts porcelain insulators date back to before the civil war for telegraph wires. Evidently the 1 to 4 line marking stamp did not securely hold the individual letters and numbers and sometimes a few letters shifted. The 55 4 is the ansi style.

In north america glass was always the predominate material for communications insulators but porcelain has become the standard for power distribution due to its greater strength and surface resistance. Tod died in 1989 and in 1991 his wife granted permission to elton gish to assign new u numbers as new styles were reported. Dry process mine insulators with this marking u 98 were possibly made by american porcelain co. Paul greaves spent countless hours verifying the many different fred locke markings on porcelain insulators.

Click on an insulator above for more information.