The scott connection accommodates the transformation of three-phase systems into biphasic or tetraphasic systems and vice versa, and in the same way as the TT transformation, two special transformers of the same ratio are used, one with a central tap and an equilibrium transformer whose tap configuration depend on the intended operating mode. In order to obtain a tetraphase system, it is sufficient to make certain changes in the secondary connections.
A tetraphase system is a biphasic 5-wire system composed of 4 phases + neutral, where each of the line voltages is 90 ° out of phase, and also the phase difference between the adjacent phase voltages.
To simulate the mode of acquisition of a three-phase three-wire system from a balanced three-phase system, one must check the phase phasor diagram for the primary (three-phase) side and the secondary (biphasic) side at the same time.
In this configuration, the balance transformer should have a tap corresponding to 86.6% of the total rated voltage of the main transformer, ie V B = V L °, where 1 V L is the primary line voltage.