What is the principal advantage of a series-wound DC motor?

The principal advantage of a series-wound DC motor is high starting torque. This motor configuration connects the field windings in series with the armature, meaning that the field current is directly related to the armature current. When the motor is started, the armature current is high due to the low initial back EMF, which generates a substantial magnetic field strength. This results in a significant amount of torque being produced right from the start, allowing the motor to handle heavy loads effectively during the initial phase of operation.

This ability to deliver high torque at startup makes series-wound DC motors particularly suitable for applications where heavy loads need to be moved from a standstill, such as in cranes, hoists, locomotives, and other heavy equipment. The design thus emphasizes robust torque characteristics at low speeds, making it an ideal choice for specific industrial applications.