The crane control will be used on the T33, A33, A40 and A45 Eco City cranes and includes Unidrive SP and Commander SK drives.
The Control Techniques solution, which was implemented in collaboration with Arcomet’s engineering department, involved fitting each rapid assembly crane with three electric motors and three drives. These were a lifting motor controlled by a 15 kW Unidrive SP, an aligning motor controlled by a 7.5 kW Unidrive SP and a turning motor controlled by a 4 kW SKC Commander. The firm said that this allowed deployment at the touch of a button and positioning with millimetre accuracy. It also featured sway dampening, use of load curves by working at maximum speed for any given weight, automatic compensation for supply current variations. Power restrictions were 20 kVA on the A30 and A40 ranges to allow easy start up via generator or mains network. There is a speed adjustment feature that uses variable rotation speed motors to achieve energy savings.
Other operational aspects that Arcomet said it believes will improve the system improved was a quiet start up with high torque without current spikes, smooth movement, iand precise positioning with counter steering during lifting and aligning movements, and controlled lifting and aligning functions.
