The 803-A8 is a Rotating Cam Limit Switch from the 803 series manufactured by Allen-Bradley. This device finds its use in machine building, automotive industry, injection molding machines, and similar applications with “repeating control” tasks. The 803-A8 rotating cam limit switch, during its shaft rotation, initiates circuit contact opening and closing at different user-defined positions. All of this happens in correlation with controlled machine movement, which has direct contact with the shaft. Moving mechanical parts tend to wear out, so designers made this part to withstand a large number of operating cycles. It can easily be paired with almost any hardware since it can be mounted in any desired plane and can perform rotations in both directions.

The Bulletin 803 devices are delivered in six special styles, with the 803-A8 limit switch is designed as “Style A”. It is delivered with 8 independent cam operator assemblies (actuating 8 control circuits, 25A normally closed cam opened contacts) and with a type 1 enclosure. The shaft extension is positioned on the (standard) left side. The 803-A8 switch, like all bulletin 803 limit switches, has a resilient mechanic design. This assembly includes a resistant steel base, rugged cast iron plates on sides, sliding and lockable cam segments (vibration resistant), a ¾ inch diameter shaft, 25 Ampere Normally Closed (NC) cam operated contacts and cable entrance openings on each side. The Allen Bradley 803-A8 switch’s dimensions are 14.51 x 5.69 x 7.88 inches (368.55 x 144.5 x 200.0 millimeters) and the weight is 16.3 kilograms (36 pounds). This unit’s working temperature range is -30 to 66 degrees Celsius (-22 to 150 degrees Fahrenheit). Not that Allen-Bradley announced the 803-A8 product as discontinued in 2007.