Sliecting thermosetting plastic, safety factor of big current is more reliable. Board type screw crinm commecting technology as structure parts. Reted AC voltage **0V. Rated current of connecting conduct piece with seven specifications of *0.**0.**0.**0.**0.**0.**0A. The cross-section *0~**0mm2, which is the biggest closure flow terminal. It can be divided into 3P. 4P flat bolt installation according to arrangement, it will be more reliable with OT. Uttermination point for connecting big current in different kind electric device.