It is the electrical connection of the motor terminals, in order to provide the same operating conditions. We can find engines with 3, 6, 9 or 12 terminals.
Three-terminal motors are built to operate only on a voltage, whether 220, 380, 440 or 760 volts.
Note:
The motor connection with three terminals to the network is made by connecting terminals 1, 2 and 3 to the network terminals R, S and T, in any order.
Currently, the terminal arrangement that is most found in three-phase motors is 6 terminals.
With this arrangement, three-phase motors can be connected at two voltages, usually for 220 and 380 volts. The motor with six terminals, to operate on a voltage of 220 v, must have its terminals connected in a triangle.
