The 803-PL6LH Rotating Cam Limit Switch with less operator cam and a left-hand shaft option is a circuit control switch by Allen-Bradley. It is used with machines with repetitive operation cycles, and in operations where the machine’s motion correlate with the cam switch’s shaft movement. The device provides circuit control using a shaft-mounted cam, which actuates contact as the shaft rotates, and it is suitable for long-lived, heavy-duty operations. The 803-PL6LH has 6 or fewer independently-operated cam assemblies, with adjustable lower (valley) and higher (lobe) cam segments, and 6 circuits with cam-opened 25A normally-closed double contact. It also has a base contact mounted cam-roller and a rotating shaft with a left-hand shaft extension and a maximum shaft speed of 400 RPM. The circuit activates when the cam lobes push against the cam roller as the shaft rotates, and the circuit is de-activated as the cam valley passes by the cam roller.

The amount of time for which the cam lobe activates the circuit (dwell time) is determined by the size of the lobes, and the device achieves its maximum dwell time when lobes offset at the highest angle, and it achieves the minimum dwell time when the lobes align perfectly. The 803-PL6LH has a timing corresponding to the moment when the cam activates the circuit, and it is determined by the position of the cam with respect to a Top Dead Center, and it has a cam duration range of 11 to 349 degrees. It has internal dwell time and timing adjustments, and the setting of both the timing and dwell time to determine the machine’s operation. The 803-PL6LH has an operational temperature range of -22 to 150 degrees Fahrenheit, with a storage level of -22 to 200 degrees Fahrenheit, and it has a NEMA Type 1 rated enclosure. This device is built for harsh industrial conditions, and it has a cast iron side plate adapted for rugged environments. The 803-PL6LH weighs approximately 8.2 kilograms (18 pounds), with a total volume of 284.1 x 181 x 138.1 millimeters (11.18 x 7.13 x 5.44 inches), and it is CE, UL, and CSA-certified.