DS

Multiple Switching Operation is a system where the street light can be energized and de-energized (switch ON and OFF) from multiple location by simply a push button switch. Figure below (A)  illustrate the layout of the street lights (L1,L2,L3…Ln) which are installed in the street of camp M. By pressing any one of the push button switches P1,P2,P3,P4, and P5 installed in buildings A,B,C,D, and E respectively, one can switch On and OFF the street lights. Multiple Switching Operation applied to lights in a camp Control Circuit Operation Figure below (B) illustrates the control circuit of a multiple switching operation. Encircled A and B maybe the power made of relay or contactors. Encircled C is the power contactor that will energized the street lights (L1,L2,L3…Ln) directly from the source. Pressing any one of the five push button switches (P1,P2,P3,P4 and P5) will energized contactor A. For example, pressing the push button switch P3 which is at the Administrator building will cause th...

If the frequency of operation of pumping liquid into a tank is to frequent, too much stress is subjected to a single motor pump. In such case the life span of the motor may not last long. To avoid to much stress to a single motor pump, it is wise to add another motor pump. The two motor are design to operate alternately. Figure (A) illustrate two motor pumps that alternately pumps liquid into tank. Control Operation Figure (B) illustrate the schematic diagram of the control circuit of the “Alternate Operation of a Two Motor Pump”. Closing the toggle switch SW will place the control circuit ready for operation. As the liquid level in the tank drops to the lower limit LL as shown in figure (A). The float switch* contact FS (1-2) will close, see figure (B). Contactor M1 (A-B) is energize by the current that flows from the line L1, toggle switch SW, float switch FS (1-2), contact M2 (11-12), contact R (11-12), contactor M1 (A-B) and to line L2. contact M1 (13-14) will close to maintain con...