A breakthrough development of the intermediate frequency melting furnace is to supply power to the two furnaces with a power supply system , thus realizing the working system without production interval operation. Practice has proved that , the total effective power of an induction melting furnace is usually not fully utilized throughout the melting period , the molten iron temperature measurement, sampling, slag, iron , especially in the case of the casting , to be cut off or reduce the power supply. If longer pouring time , utilization rate of only 50% or so , in order to achieve the desired productivity , the power supply shall be rated power utilization rate of 90% of 118 times. In order to solve this problem , a dual power system was successfully developed. The system uses two identical inverters and capacitor banks , one for each furnace , but all powered by a common rectifier and transformer. Each converter can be individually controlled , it can be a total effective power allocated to the two in any proportion furnace. In addition to providing sufficient power for the insulation of one furnace , the rest of the power can be used to melt the molten iron in another furnace. This kind of power supply can realize the power transmission to the two furnaces at the same time , completely avoiding the switch or adding a set of power supply , without having to be in the melting process .Frequency power switch to the holding furnace body , in order to maintain the necessary casting temperature , so as to achieve melting and holding two functions. When a furnace is in maintenance , the power supply can be isolated from the furnace , and only the other furnace is powered , which also increases safety.