The Allen-Bradley 803-A12R is a rotating cam limit switch in the Bulletin 803 Series. It has 12 circuits available, as well as a speed reducer with a gear ratio of 20:1. Like other Bulletin 803 series Style A switches, it is equipped with a standard left-hand shaft extension, 25A double-break contacts that are N. C. or normally closed contacts, a cam duration ranging from 14 degrees minimum to 346 degrees maximum depending on what angle of shaft rotation is needed, and a maximum shaft rotation speed of 150 RPM. The 803-A12R switch has a Type 1 enclosure and it can be mounted on any flat surface plane. The 803-A12R can rotate in either a clockwise or a counterclockwise direction and it is also equipped with internal dwelling adjustments and timing adjustments, which can only be set when the cam limit switch is not in motion, and it is equipped with a spring-loaded cam-roller assembly which is mounted on the contact base. Its approximate weight is 45 pounds. 

This series of Allen-Bradley Bulletin 803 switches, including the 803-A12R switch, have typical shaft torques of 7 pounds on an inch when the cam roller rides up the cam ramp, shaft torques of 3 pounds on an inch when the cam roller rides on the lobe, and typical shaft torques of 0.5 pounds on an inch with the cam roller is in the valley. The working temperature of this rotating cam limit switch is between -30 and 66 degrees Celsius and its storage temperature is between -30 and 93 degrees Celsius. The 803-A12R rotating cam limit switch is suitable for use with machines which have operation cycles that are repetitive, particularly those whose motion and shaft rotation are correlated to each other because the 803-A12R can easily handle heavy-duty operations and it has a long product life.