An electric motor converts electrical input into mechanical torque and shaft power through electromagnetic interaction. DC, induction, synchronous and electronically commutated machines use different field-production and commutation methods. Their useful operating ranges depend on supply, winding and magnetic limits, cooling, speed, torque and duty cycle.
The articles below cover motor principles, types, starting, commutation, control and testing. Select the complete motor-driven system for the load rather than choosing only a nameplate power. Check starting current and torque, speed-torque curve, efficiency at the expected load, enclosure, insulation class, temperature rise, service factor, drive compatibility and protection. A variable-frequency drive can save energy on suitable variable-speed loads, but its losses and motor effects must be included.
