The 803-PL8W Rotating Cam Limit Switch with a “Less Cam” option is a circuit control device from Allen-Bradley that is used with heavy-duty machinery that has repetitive operation cycles, and it is used with applications that have long-life/heavy-duty operations, where motion directly correlates with shaft rotation. It uses shaft mounted cams, which actuate circuit contacts while the shaft rotates, and it is used in applications like assembly/packaging, steel molding, and waterway gate/lock operations. The 803-PL8W has 8 cam-opened circuit contacts, with 8 or fewer cam assemblies, and it comes with a spring-loaded cam-roller and a rotating shaft with a 400rpm base speed and over-sized ball bearings. Circuits are actuated when the cam lobe brushes against the cam-roller assemblies, and it opens the 25A N.C. double-break contact, and it de-activates when the cam valley passes by the cam-roller. The Normally-Closed (N.C.) contact has a continuous carrying current of 25A, with a MAKE/BREAK AC contact rating of 150/15A at 120 Volts AC, and a MAKE/BREAK power rating of 1800 Volts A. The 803-PL8W has a keyway (slot) on the rotating shaft, which connects machines to the shaft, and the device has a sequentially-set timing function (measured in degree), that is determined by the cam segment’s position on the shaft, with respect to the Top Dead Center/Keyway.

The 803-PL8W also has a dwell time (the duration of circuit activation) determined by the size of the cam lobe, and it provides the maximum dwell time when the cam lobes offset at the maximum angle, and the minimum dwell time happens when cam lobes align perfectly. It has an internally adjusted timing and dwell time, which cannot be set while in motion, and the cam timing and dwell time settings determine machine control and operation. The 803-PL8W has a lesser cam option, and the switch comes with an external adjustment sprocket, which allows for changing the position of the driving mechanism relative to the rotating shaft. The 803-PL8W has functioning temperature limits of -30-66 degrees Celsius (-22-150 degrees Fahrenheit), with storage limits of -30-93 degrees Celsius (-22-200 degrees Fahrenheit), and it comes in a NEMA 1 rated enclosure. The device weighs approximately 10 kilograms (22 pounds), with total dimensions of 483.3 millimeters x 181 millimeters x 138.1 millimeters, and it is CE, UL, and CSA-certified.