The 803-B4X Rotating Can Limit Switch by Allen-Bradley is a heavy-duty circuit control switch with a double shaft extension and a NEMA Type 1 rated enclosure used for the control of industrial machinery with repeating operation cycles where the machine motion correlates with the shaft rotation. It operates through a shaft-mounted can which actuates circuit contact as the shaft rotates and it is designed for rugged heavy-duty operations with long operation life. The device comes with 4 heavy-duty circuit controls, with a 10A snap action contact, and it has 4 cam assemblies with adjustable cam segments which operate independently. The 803-B4X has a spring-cam roller mounted on a contact and a rotating shaft with a 150 RPM shaft base speed, and a keyway for connecting machines to a rotating shaft. When the shaft rotates, the cam segments rotate, and when the higher adjustable cam segments (lobes) push against the cam roller, the circuit activates, and when the lower can segment (valley) passes by the cam roller, the circuit deactivates.

The 803-B4X has a dwell time corresponding to the duration of cam activation which is determined by the size of the cam lobes and which can be either minimum or maximum depending on the angular alignments of the cam lobes. It also has a timing in the degree corresponding to the moment of cam activation, and it is determined by the position of the cam with reference to the keyway position, and it has a cam duration range of 14 to 346 degrees. The 803-B4X has internal dwell time and timing settings, and it comes with factory modified double shaft extension. It has a working temperature range of -30 to 66 degrees Celsius (-22 to 150 degrees Fahrenheit), with a storage level of -30 to 93 degrees Celsius (-22-200 degrees Fahrenheit), and it has a NEMA Type 1 rated enclosure. The 803-B4X weighs around 10.9 kilograms (24 pounds), with a shipping volume of 144.5 x 82.6 x 177.8 millimeters (5.69 x 3.25 x 7.0 inches), and it is CE, UL, and CSA-certified.