Standard power consumption for steel induction furnace is 625 kWh/ton. Using this information induction power supply capacity can be select using following calculation.
Let desired yearly production is 2000 ton in steel induction furnace Therefore daily production would be 2000/240 day = 8.33 ton/day (base of 240 working days in a year. Hourly production = 8.33/16 [ base on two shift (16 hours) in a day]
= 0.520 ton/ hour
=520 kg/hour (1 ton = 1000kg)
Required power = (520 kg/ hours). 625 kWh/1000 kg
= 325 kW
Therefore required power supply will be 364 kW in steel induction furnace
Calculate Melting Rate
Melting rate for steel @325 kW can be calculate using following method.
325 kW 625 kWh
———————————— = ———————
Weight of the metal in kg (x) 100 0 kg 
Solve for Weight of the metal x = 520 kg/hr
Calculate Melting time
If the nominal capacity of the steel induction furnace is 550 kg and selected induction power supply is 325 kW, then melting time to melt 550 kg of steel @325 kW can be calculated using below method.
325kW. Time 625kW . 1 hr
————————————– = ————————————
550 kg 1000 kg
Solve for time
Time = 1.06 hours
=64 minute
Using above method power supply can be select for other metal. Power consumption at standard kW/kg ratio for some metal as per follow:
Cast Iron melting: 550-600 kWh/ton
SG Iron melting: 550-650 kWh/ton
MS/SS melting: 600-680 kWh/ton
Aluminum melting: 650-700 kWh/ton
