Furnace Transformers are Transformers which are specially designed for powering Arc Furnaces. These Transformers are designed to withstand high currents and severe voltage fluctuations. They are also designed to withstand higher than normal temperatures.
The windings are mechanically strengthened to withstand the huge forces generated due to the flow of high currents. Reactors are often used to smoothen the fluctuations. Operation of the Furnace breaker which can trip frequently generates surges and operational over voltages.
Furnace Transformers are designed to provide On load or no-load tap Changer. They also have a built in reactor for long arc Stability. The bushings can be air cooled or water cooled.
Transformers for DC Furnaces have an attached rectifier. DC Furnace Transformers are also designed to withstand the harmonics generated by the rectifier operation.
Furnace Transformers are generally used in the steel industry for smelting iron and refining steel.