The 803-B24 is a Bulletin 803 Rotating Cam Limit Switch manufactured by the Allen-Bradley brand.  Like the Rotating Cam Limit Switches, the 803-B24 also has a rotating shaft and a spring-loaded cam-roller inserted on the contact base. It also has two fully functional circuits. When the shaft makes a rotation, the cams activate the contacts. The 803-B24, which is type 4 & 13 enclosure, weighs 15.9 kilograms. Its dimensions are also about 18 x 13 x 10 inches, enabling it to be used as a heavy duty control circuit instrument on appliances that have a recurrent cycle of operation where movement is connected to the rotation of the shaft. These appliances include locks, rotary tables, mechanical presses, packing machines and injection molding machines. It is also applicable in the production of steel and heavy metal.The Rotating Cam Limit Switch has timing adjustments and internal dwell. It also has a left shaft extension.

Timing, when the circuit is activated by the cam, is influenced by the cam’s position on the shaft. The circuit is set in motion by the lobe that presses against the cam roller assembly. The lobe is usually on top of cam segments. The amount of time spent by the cam lobe to actuate the circuit (dwell time), is determined by the vastness of the cam lobes and the cam segments’ positioning. The maximum shaft speed of the 803-B24 switch is 150 revolutions per minute (RPM). The 803-B24 is a Single Pole, Double Throw (SPDT), snap action switch that has a rating of 10A. This means that when the cam-roller is brought into operation by the cam lobes, the contacts snap over. Therefore, the (N.O) normally open contact closes and the (N.C) normally closed contact opens. It is advised that the dwell adjustment and the internal timing should be made when the appliance is not in motion. To make modifications, detach the cover, loosen cam bolts and set the cams to the appropriate position by rotating them. After the cams are in the desired position, make sure the bolts are tightened and fix up the cover.