Allen Bradley’s 803-A104 rotating cam limit switch belongs to the 803 series of limit switches. The 803-A104 is meant for heavy-duty applications and can be installed on a shaft through the use of a rotational motion transfer system. Its ten eccentric cam assemblies are spring loaded and utilized to make contact with ten different circuit devices. A pair of separately adjustable cam segments is present in each cam, and the complete spring-loaded roller cam assembly is mounted on a shaft with a maximum rotational rate of 150 RPM. The use of separate speed reducers that have a variety of gear ratios will allow a user to operate the 803-A104 device with an extensive range of RPM. A total of ten cams, all different, help choose a variety of shaft location actuations while contained in the full 360 degree rotation cycle for contact initiation. A Normally Closed (N.C.) double break type contact with a 25A current rating is provided in the 803-A104 switch.

This switch can be used for a minimum of 14 degrees to a maximum of 346 degrees for a dwell angle. The rugged nature of the device allows it to be used in a variety of machines including water-way gates, assembly machines, injection moulding machines, and presses. The 803-A104 is available in Type 4 and Type 13 enclosure options. It has dimensions around 29.75 X 24.5 X 21.69 inches and an approximate shipping weight of 60 pounds. To control the dwell and timing, adjustments must be made internally to the 803-A104. These adjustments should be made exclusively when the switch is completely inactive. In order to make these adjustments, remove the switch’s cover and loosen its cam bolts to access the cams. Scales are provided on either shaft and on the mounting plate in order to simplify the setting process. When the cam adjustments are complete, tighten the cam bolts and replace the cover. Operation of N.C. contacts is possible on a 50 to 60 Hertz frequency and a 120 to 600 Volt AC supply, or a 115 to 250 DC supply.