The 803-PL12 Rotating Cam Limit Switch by Allen-Bradley is a heavy-duty circuit control switch with standard left shaft extension and a NEMA Type 1 enclosure that is used with machines that have dedicated cyclic operations, where the shaft rotation correlates with the machine’s motion. The 803-PL12 uses a mechanical shaft-mounted cam for contact actuation and it is suitable for industrial applications like packaging/assembling, steel forming, and injection molding processes. The device comes with 12 cam-opened circuits, and 12 independently-operated cam assemblies with adjustable higher and lower segments, but it can operate with lesser cams. The 803-PL12 also comes with a spring-loaded cam-roller assembly, with a 400 RPM base speed-rotating shaft with over-sized ball bearings, and a keyway slot which connects the rotating shaft to the machines. When the shaft rotates, the higher cam segment glides through the cam roller, and the 25 A Normally-Closed contact with AC and DC contact ratings opens contacts, and the circuit is activated, and when the lower cam segment passes by the cam roller, the circuit is deactivated.

The 803-PL12 switch has a dwell time corresponding to the duration of the activation time, and which is determined by the size of the higher lobe, and it has a timing corresponding to the time of activation as the cam rotates and which is a function of the cam position relative to the keyway. It has a maximum dwell time when the lobes are offset at the maximum angle, and a minimum dwell time when the lobes align, and like every Style P device, it has a cam duration range of 11 to 349 degrees. The 803-PL12 has high-speed internal dwell time and timing settings which influence machine operations, and the switch comes with a standard left 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 to 200 degrees Fahrenheit), and it is enclosed in a NEMA Type 1, indoor-rated enclosure. The 803-PL12 has a net weight of 13.6 kilograms (30 pounds), with approximate dimensions of 483.3 x 181 x 138.1 millimeters (19.04 x 7.12 x 5.44 inches), and it is CE, CSA, and UL-certified.