Reversing Electric Drive

an electric drive in which the rotation of an actuating motor or the motion of an actuating mechanism is realized in two (usually opposite) directions.

The direction of rotation of an AC actuating motor that draws power directly from a polyphase AC network is reversed by means of contactors that can change the cycling sequence of the phase voltages from the power source. An AC actuating motor that is supplied through static (rectifier) frequency converters is reversed by changing the cycling sequence of the phases of the master generator in the converter’s control system. In a DC actuating motor, for which the torque at the motor’s shaft is proportional to the product of the armature current and the excitation flux (taking their signs into account), reversal is achieved by changing the direction of the current in either the circuit of the armature winding or the circuit of the exciting winding.

In electric drives with electromagnets, reversal of the actuating mechanism, which is linked to the core of the electromagnet, is accomplished by means of contact or contactless switches that reverse the direction of the current in the coil of the electromagnet.