ABB recently received an order to supply twelve drive systems for two grinding plants in Indonesia. The main contractor Loesche GmbH is managing the project. The drive systems will be installed in the Semen Tonasa and Tuban cement plants, owned by the Semen Gresik Group, and located at Biringere, Pangkep, South Celebes/Indonesia. Commissioning was scheduled for the end of 2010. Grinding plants have become a technically and commercially attractive solution to supply local consumer centers with cement at a low investment cost. ABB’s scope of supply consists of six drive systems for each plant: two 5500 kW mill drive systems for the vertical mills, two 2400 kW mill fan drive systems for the mill fans and two 355 kW separator drive systems for the mill separators. The mill drive is powered by a fixed speed wound rotor induction motor, the mill fan drive by a variable speed ACS5000 system and the separator by an ACS800 drive system. The most efficient drive in this power range, the air-cooled ACS5000 was selected because of its performance, the lack of cooling water available on site and its network friendly behaviour.