In addition to the above, factor which contributes to increased power consumption is.

• Low power factor

• Low input voltage

• Frequent failure of power supply.

• Asbestos thickness and rammed lining thickness, more than recommended.

• Heavily patched/ repaired furnace lining.

• Frequent emptying of furnace and cold starts.

• Average level of molten metal low in furnace in operation.

The power requirement per tone of molten metal for different types of charge materials is as follows: (approx)

For various combinations of charge materials intermediate figure are application.
In super heating, generally 50 units per tone of molten metal per 1000C rise in temperature are observed. Also the melting/super heating power consumption is higher per ton with smaller furnaces.