12kV 630A Oil-filled four-position load switch is designed for ring-type US-box ring change cabinet designed to meet the IEEE, IEC and GB standards of all requirements. Can be used in grounded or underground systems.  Oil-immersed four-position load switch in the installation, close to the transformer core can minimize the internal connection Cable capacitance, and thus significantly reduce the loop in the ferromagnetic resonance. Both side mounting and top mounting are available For general American box transformer or buried transformer.