September 30, 2013 – Weg Electric offers a three-phase, wound rotor, induction motor with motorized/manual brush lifting system to the mining market, claiming they are suitable in applications involving high-inertia loads and torque, along with low starting currents.

After the motor starts, the system short circuits the rotor phases and lifts the brushes, avoiding permanent contact with the slip rings; the motor then operates like a low-maintenance squirrel cage motor in continuous-duty, says Weg, eliminating the need for frequent monitoring and brush replacement. The key to this system is an electromechanical actuator with control switches that can be set to precisely lift and lower the brushes when needed, says the company.