The problems of using a typical frequency converter in metal melting in an induction crucible furnace are considers along with the test results obtained. The process of melting cast iron in a furnace with a capacity of 3 tons is analyzed. Two methods of dual-frequency power supply of induction crucible furnaces are proposed to ensure stable operation of the converter and high efficiency throughout the melting cycle. Graphs and characteristics of the furnace operation are given in relative units.