Power engineers operate and maintain reactors, turbines, boilers, generators, stationary engines and auxiliary equipment to generate electrical power and to provide heat, light, refrigeration and other utility services for commercial, institutional and industrial buildings and other work sites. Power systems operators monitor and operate switchboards and related equipment in electrical control centres to control the distribution of electrical power in transmission networks. They are employed by power generation plants, electrical power utilities, manufacturing plants, hospitals, universities and government and commercial establishments. Apprentices are also included in this unit group.