Soft start technology
MacGregor, part of Cargotec, has introduced a new electric starter cabinet for hydraulic hatch cover power units on bulk carriers and general cargo ships. It features an intelligent ‘soft-start’ function that avoids starting current peaks and reduces stresses on mechanical and hydraulic components.
“A ship has a closed electrical system and so current peaks may cause disturbances elsewhere in the system. Therefore when high-powered motors are introduced into hydraulic systems, it is important that the starting process is carefully controlled,” says Mika Åback, MacGregor Technical Manager, Control Systems. “For a heavy-duty electric motor the starting current peak can be up to ten times its operating current at its nominal running output power, and so it is important to reduce this demand peak on the ship’s electrical supply.”
Soft-start technology significantly reduces starting peaks to around four times a motor’s nominal running output power. It replaces the existing standard solutions, which are direct on line starting, or optional stepped starting via Star Delta technology.
