The 803-B104 Rotating Cam Limit Switch is a circuit control device by Allen-Bradley that is used with heavy-duty machinery with dedicated cycle operation in applications where the machine’s motion directly correlates with the shaft rotation. It is a device in the Style B series, and like all Allen-Bradley 803 Style B devices, it comes with a factory-designed standard left-hand shaft extension, and it is enclosed in a NEMA Type 4 and 13 rated enclosure. The device is made for long-lived, heavy-duty operations, and it is suitable for industrial applications like Waterway Gate/Lock Operations, Assembly and Packing processes, and Injection Molding operations. The 803-B104 has 10 circuits, with a snap action contact block assembly, a spring-loaded cam roller, 10 cam assemblies, and a rotating shaft with a 150rpm base speed. Each cam in the device has an adjustable lobe and valley segment, and the device also comes with a slot in the shaft (keyway) which connects the rotating shaft to the machine. The circuit is activated when the cam lobe brushes against the cam roller, and the total time lapse of the activation (dwell time) is determined by the size of the cam lobe, and when the cam valley passes through the cam roller, the circuit then deactivates.

The 803-B104 has a set cam timing measured in degree, determined by the position of the cam on the shaft relative to the keyway (TDC) position, and like all the Style B devices, it has a cam duration range between 14 and 346 degrees. The 803-B104 comes with a 10A Snap Action Contact with 1 Normally-Closed and 1 Normally-Open Contact, and with maximum AC and DC ratings of 15/1.5A MAKE/BREAK ratings at 480V AC, and 0.1A at 550 to 600 Volts DC, respectively. The 803-B104 has working temperature limits of -30 to 66 degrees Celsius (-22 to 150 degrees Fahrenheit), and storage limits of -30 to 93 degrees Celsius (-22 to 200 degrees Fahrenheit). It weighs approximately 19.1 kilograms (42 pounds) with approximate dimensions of 411.2 millimeters x 144.5 millimeters x 200 millimeters (16.19 inches x 5.69 inches x 7.88 inches), and it is CSA, UL, and CE-certified.