The 803-B5RH Rotating Cam Limit Switch from Allen-Bradley is a heavy-duty control switch with shaft mounted cams. It is used with industrial machinery that has a long life and repetitive operation cycles, and in applications where machine motion corresponds to shaft movement. The 803-B5RH is built for industrial processes such as steel forming, packaging, assembling, and injection molding, and it is covered with industrial-grade cast iron side plates. It has 5 independently-operated cam assemblies with adjustable upper and lower segments (the lobes and valleys), and it has 5 circuits with a 10A snap action block contact. The device also has a rotating shaft with a 150 RPM base shaft speed, and a contact-mounted spring-loaded cam-roller, which activates the circuit as the cam lobes press against it.

The 803-B5RH’s snap-action contact has a 10A carrying current, with AC and DC contact ratings, and when the shaft rotates, the cam lobes push against the cam roller and Contacts 1 and 2 open, while Contacts 3 and 4 close. The 803-B5RH has a dwell time which corresponds to the size of the lobes, and it can achieve its maximum dwell time when the lobes become offset at the largest possible angles, and the dwell time is at the minimum when the cam lobes align. It has a timing that is measured in angular degrees corresponding to the position of the shaft-mounted cam, relative to the keyway/top dead center, and it has a cam duration range of 14 to 346 degrees. The 803-B5RH has a factory-modified right-hand shaft extension, unlike the standard left shaft extension on most Style “B” devices, and it has internal dwell timing and timing adjustments. It also operates at a temperature range of -30 to 66 degrees Celsius (-22 to 150 degrees Fahrenheit), with a storage temperature range of -30 to 93 degrees Celsius (-22 to 200 degrees Fahrenheit), and it comes in a NEMA 1 rated indoor enclosure. The 803-B5RH has shipping dimensions of 301.6 x 82.6 x 177.8 millimeters (11.88 x 3.25 x 7 inches), with an approximate weight of 22.2 kilograms (49 pounds), and it features CE, CSA, and UL certifications.