Introduction to Industrial Automation

Figure 3.25  Automated filling of a tank.

---

Industrial Automation Synthesis 

◾

 

101

operation, while assuming that the water supply of those pumps covers the requested demand. 

With the operation of the two pumps and a low demand, the tank will continue to fill up, thus 

if the level becomes bigger than the E

1

 level, one pump will operate (relay C

2

). If the level of the 

tank continuously increases and extends to level E

2

, none of the pumps will be in operation. If the 

water level starts to drop again, then one pump will start operating again as soon as the level drops 

below E

2

. Throughout the time where the level remains in between E

1

 and E

2

, the demand will be 

equal to the provided supply, while only one pump will continue to operate. In this automation 

approach, attention should be paid to the configuration of the level sensors’ electrodes, which in 

this case, have been put approximately on the same level.