The cabinet is suitable for three-phase four-wire and three-phase five-wire power system with three-phase AC 50Hz/60Hz and rated working voltage 380V/400V. It is widely used in the places for high power quality, such as automobile manufacturing, power plants, industrial and mining enterprises, etc. This equipment can realize the automatic compensation of reactive power, stabilize the electric energy, reduce the loss, save the electricity and obtain remarkable economic benefits.