UNDRIVES RETROFITTED TO FLOATING GRAB CRANES CUSTOMER PROFILE Four floating grab cranes in Amsterdam, mainly used for ship to quay bulk handling, have been retrofitted with drives from Control T echniques. The two 16-tonne cranes with AC Unidrive variable speed drives, the two 25-tonne cranes have been fitted with Mentor II DC drives. KEY BENEFITS • COST SAVINGS • EASY TO PROGRAM • ENERGY EFFICIENT • EXTREMELY RELIABLE • EASY TO MAINTAIN THE CHALLENGE On conventional cranes the slewing motion is controlled by a system of slip-ring motors and rotor resistors, which doesn’t work well at low speeds. The sudden changes in torque between resistor steps waste energy and the system requires regular maintenance. When replacing the slip-ring motors with a modern drive system the

Join for free to read