The 803-A2R Rotating Cam Limit Switch by Allen-Bradley is a heavy-duty control device with 2 cam circuits that is used with industrial machinery that has repetitive cycles in operation where the machine’s motion correlates with the shaft speed. The device, like every other in the Bulletin 803 Series, has a rotating switch with a cam mounted on a rotating shaft, and it is built for long-life/heavy-duty operations. The 803-A2R has 2 independently-operated cams, with 1 normally-closed contact, and a rotating shaft with 150 RPM of maximum rotation speed. The device has a cam with adjustable lower (valley) and upper (lobe) segments, with a keyway (slot) that is used for connecting the rotating shaft to machines, and it has a spring-loaded cam roller assembly. The 803-A2R circuit is activated when the spring-loaded cam roller makes contact with the cam lobe, and the activation is timed as a measure of degree (timing), which is determined by the position of the cam on the shaft relative to the keyway/TDC position, and it is deactivated when the lower cam segment passes over the spring-loaded cam roller. The activation has a lasting period called the dwell time, which is determined by the size of the lobe, and the device has a cam duration timing range of 14 degrees to 346 degrees. The 803-A2R comes with a standard speed reducer, with a 20:1 gear ratio, and it is designed with a left-hand shaft extension. It has a functional temperature range of -22 degrees Fahrenheit to 150 degrees Fahrenheit, with a -22 to 200 degrees Fahrenheit storage temperature range, and it comes in a NEMA type 1 rated enclosure. The 803-A2R weighs approximately 20 kilograms (9.1 pounds), with shipping dimensions of 111.1 millimeters x 144.5 millimeters x 200 millimeters (4.38 inches x 5.69 inches x 7.88 inches), and it is UL and CSA certified.