Problem:     Our customer was a supplier of submersible pumps for pumping gasoline. The client wanted a pump drive controller that would maintain the pumps output pressure so that the volume of gasoline dispensed at the nozzle would be constant regardless of the number of gasoline dispensers operating at that time. Our customer also provides leak detection and other related equipment to this industry and wanted the controller to be able to perform the leak detection tasks and interface to their other equipment across a LonWorks® network.

Solution:     The final design implemented a 5HP variable speed drive that would power the pump's 3 phase electric motor. A separate pressure transducer was used to measure gasoline pressure. The controller automatically varies the motor speed to maintain a constant head pressure in the gasoline lines. Additionally, the pump controller implemented the leak detection algorithms so that a single package provided the basic pump and leak detection functions needed in a gas station.

The controller drive algorithm can be tailored to a particular pump/motor combination through direct interaction with the operator using a separate hand held programming device, or alternatively over the LonWorks network.

This product was also required to be "fail safe" and underwent extensive qualification testing at UL to insure that it could be used in this hazardous environment.