Of the current transformer is put the bus bar type current transformer, for rated frequency is 50HZ, the working voltage of 0.66KV and the following measurements in the AC line current, electric energy measurement and relay protection, can still do more. The voltage transformer iron core is circular and rectangular iron core, evenly distributed along the circumference of the iron core of secondary winding, transformer insulation is made of flame retardant ABS plastic shell. For use by the bus route around the Middle window, uniform winding of the transformer secondary winding, magnetic flux leakage is very small, with stable performance, light weight, easy installation and so on.