Siemens 3SB03-3MKB Selector Switch 3 Position

Siemens 3SB03-3MKB is a 30 mm diameter selector switch with a black operator knob, built for panel-mount control in industrial automation environments. The device offers three positions in a maintained configuration, enabling manual selection between circuits without a return-to-center action. Distributors and catalogs consistently describe this exact variant as 30 mm, 3-position maintained and knob-actuated, with the manufacturer (Siemens via Furnas Electric Co) noting the model as 3SB03-3MKB. Several listings indicate this model has been discontinued by the manufacturer, which can affect availability but confirms the precise part number and configuration. When sourcing for repairs or replacements, confirm that the mating contact blocks and mounting hardware match the 3SB03-3MKB specification to ensure proper fit in Siemens/Furnas 30 mm switch assemblies.