The power supply voltage of resistance furnace is mainly determined according to the power supply situation and the requirements of furnace use. Resistance furnaces generally use 380 V or 220 V power supply directly. Some electric furnaces must use very low voltage because of special requirements, and need to install transformers to achieve the purpose.
In general, 220V series or parallel series power supply is adopted for resistance heating elements with power below 25KW, and 380V star or triangle power supply is adopted for resistance furnaces with power between 25KW and 75KW. For resistance furnaces with a power of more than 75KW, the power supply mode of electric heating elements is relatively diversified. The purpose is to make each heating element have an appropriate amount of power, which is convenient for component manufacturing and furnace power and temperature control.