The smelting equipment with one series and three series lines is equipped with a transformer of 4000 kVA, and the ideal effect is achieved: firstly, the molten iron of various specifications of castings is provided by a fixed furnace, the material is stable and stable, and the reliability of product quality is guaranteed; followed by three furnaces At the same time, the same or different operations (melting, heat preservation, casting), in 24h or even 360d uninterrupted operation state, the production capacity is increased by about 30% than "one belt one"; third, the power factor of equipment operation is always >95%, and because of three The electric furnace only uses one power supply (transformer). The power of the three electric furnaces can be automatically adjusted. It has been in full-load operation state, the equipment utilization rate is almost 100%, and it has maintained a high thermal efficiency state. Therefore, it is more energy-efficient than the “one belt one” traditional equipment. 25% or so.