It can be said that it is quite common for the technicians responsible for the operation of the electric machines to remove the same ones that are operating at full voltage, in order to take full advantage of the starting torque. In the event of a full voltage starting of an electric motor causing a possible voltage drop, greater than the determined maximum, it is necessary to use a starting option with a lower voltage, always analyzing if the torque is sufficient enough to drive load. The first mode of supply is direct current to normal voltage, allowing the motor to connect to the grid with the winding for high voltage.
Another way of reducing the starting voltage is to supply a less-than-normal voltage current through resistors, inductors or autotransformer. If it is necessary to carry out the connection of machines to a public electricity network, it should be noted that it is necessary to observe the specific indications for a specific purpose, in accordance with current regulations. The reduced voltage starting systems have the disadvantage that the starting torque is smaller in proportion to the square of the voltage reduction which is supplied to the motor.