Star Delta starting is the best known and perhaps the most widely used low voltage starting method.
It is used to start the pump's motor wit lower levels of mechanical stress and with current limitation during start-up; it does this with the aid of a timed system which switches the control contractors installed inside the panel.
Star-delta starting reduces starting current and torque to values of 33% (1/3) of those measured during direct starting.
During start-up, the currents flowing through components are lower than the motor's related current.
In consideration of environmental relief and energy saving Franklin Electric developed a High Efficiency 6" Submersible Borehole System, consisting of a synchronous submersible NEMA motor associated variable frequency drive and output filter.