Product brief introduction Product Introduction FYSeries current and voltage Transformer Load Box is specially provided for various payloads when testing current and voltage transformers and it is an ideal matching product for various transformer verification devices.The Transformer Load Box is in strict accordance with the national standard jjg313-94 JJG314-94 design for.Its Transformer Load Box output capacity is large Full range of loads in light weight-looking appearance Stability and other advantages.