Testing and calibrating current transformers often requires standard burdens of reliable accuracy and stability, and burdens that are immune to stray fields and harmonics. These burden sets have been carefully designed to meet these requirements. They also provide the standard burdens required for the testing of current transformers for metering service, and for the testing (within the current rating provided by the sets) of current transformers for relaying applications, all as called for by IEC (International Electrotechnical Commission) Publication 185: 1987.

The burden sets are of the portable type, supplied in black metal housings with engraved bakelite panels. Extensive design and development work in perfecting these burden sets, and the quality material and skillful workmanship employed assure excellent performance and quality throughout. Details pertaining to the accuracy and performance, as well as other specifications, are given below.