Here is an example, if there is a pump box over flowing. The effect is that the pump is overflowing. What we want to know is, what is the cause? Mechanical failure? Electrical? Perhaps an Airlock?
First, go to the pump itself, remember the purpose of a pump is to deliver slurry from one point to another, so be sure the impeller shaft is turning. Don’t check the drive motor to see if it is running then assume that the pump is turning. The belts could be burnt off of it or a shaft coupling could be broken.
Never assume anything –> “VERIFY”. If everything seems to be al-right electrically and mechanically, check the pump delivery rate, the discharge line or pump box may be partially restricted. If the pumps output is O.K. then it is somewhere else in the circuit. You then go to the piece of equipment that feeds the pump and eliminate the variables that effect it. You continue to check out your circuit in this manner until you discover the cause.