The 803-A8X Rotating Cam Limit Switch by Allen-Bradley is a Style A circuit control device that is used with heavy-duty machinery with repeating operational cycles in applications where the machine motion correlates with shaft rotation. The 803-A8X uses a shaft-mounted cam which actuates the contacts as the shaft rotates for operation, and it is built for heavy duty and long-term industrial operations. The device comes with 8 cam assemblies with adjustable higher (lobes) and lower (valley) segments which operate independently of each other and it has 8 control circuits with 25A normally closed double break contacts. The 803-A8X has a rotating shaft with a 150 RPM shaft speed, and an over-sized ball bearing, and it comes with a contact-mounted cam roller assembly which activates the device's circuit as the can lobes brushes it. The device is deactivated when the cam valley passes under the cam roller assembly, and the duration of the cam activation (the dwell time) which depends on the length of the cam lobe depends on the angular displacement of the cam lobes.

The 803-A8X achieves its biggest dwell time when the cam lobes offset at the maximum angle, but it reaches its minimum dwell time when the cam lobes are aligned perfectly, and it has a timing (the moment of cam activation) that is determined by the position of the cam on the rotating shaft, with respect to the position of the Top Dead Center/Keyway. The 803-A8X has internal dwell and timing adjustments, and unlike the standard models in the Style A series, it comes with a double shaft extension. It has working temperature limits of -30 to 66 degrees Celsius (-22 to 150 degrees Fahrenheit) without impeding contact performance, and it can be stored at a non-operating temperature range of -30 to 93 degrees Celsius (-22 to 200 degrees Fahrenheit). The 803-A8X comes in a NEMA Type 1 indoor rated enclosure, and it is CE, UL, and CSA certified. It weighs approximately 16.3 kilograms (36 pounds), and it has shipping dimensions of 311.2 x 144.5 x 200 millimeters (12.25 x 5.69 x 7.88 inches).