This Rotating Cam Limit Switch, the 803-A4 Bulletin 803, is manufactured by Allen-Bradley. It is designed to operate on machines that have powerful hardware in a repetitive cycle of operation. The 803-A4 rotating cam limit switch follows mechanism movement with correlated shaft rotation. Its shaft rotation starts contact actuation (closing and opening) at various angular positions. All of the parts on the 803-A4 rotating cam limit switch device are built durably, with high quality to endure a heavy duty operation. The 803-A4 can function equally well in any plane, and with either rotating direction. The 803-A4 is supplied with four independent heavy duty adjustable cam segments. They actuate four 25 A current rated normally closed double break contacts. The device is built in type 1 enclosure. Its shaft extends to the left when looked at from the face side of the switch.

The 803-A4 assembly is made of a base of steel, a 0.75 inch diameter shaft, iron side plates, double break contacts (25A current rating), adaptable cam segments fixed with locking nuts, and cable glands. The bulletin 803 “Style A” devices, such as the 803-A4 rotating cam limit switch, have internal dwell and timing setting options. The user can perform this setting only when the device is in an idle state. To do so, the cover must be removed, the cam nuts released and the cams rotated to the desired angular defined position. Then the user should tighten the cam nuts to make this cam position fixed, and finally return the cover. The Allen-Bradley 803-A4 dimensions are 7.88 x 5.69 x 7.85 (200.1 x 144.5 x 199.4 millimeters) and its shipping weight is approximately 22 pounds (10 kilograms). The 803-A4 can operate at temperatures between -22 and 150 degrees Fahrenheit (-30 to 66 degrees Celsius). Production of the 803-A4 was terminated in 2007.