ABB’s hum-free installation contactor designs offer a wide range of ratings from 16 A to 100 A. Widely used in buildings for switching and controlling lighting, heating, ventilation, motor and pumps, the installation contactors take noise reduction to a new level. With an innovative AC/DC design that eliminates hum, a selection of tool-free accessories as well as manual and automatic versions, installation contactors offer peace of mind in noise-sensitive applications.