SETCON Servos help the Main drive to operate more efficiently, avoid overloads, costly equipment damage, and downtimes. Surely, it is all about SETCON Soft-Start mode. This integrated technology allows to start up the whole drive train very smoothly, with a minimum time of inrush currents.
The frequency controlled SETCON Servos gradually ramp up the whole pump string from 0% speed and acting as so-called pony motors. While starting, the Main drive is disconnected from the high-voltage (HV) grid, until the Main drive reaches synchronous speed, at a pump speed of app. 50%. Herby, the Main drive´s rotor is rotating in unison with the entire drive train to build up the necessary magnetic flux. Now by connecting the accelerated Main drive to the HV grid, the time for inrush currents is reduced significantly, in comparison to DOL (direct online) starts.
The SETCON Soft-Start mode is one of the most efficient solutions for reducing inrush current as the device enhances the voltage gradually and without stress for the system. Therefore, SETCON is cost-effective in comparison with, i.e., a Main drive overload protection system, which may cause additional losses of overall drive train efficiency.
An inrush current is a time limited, very high current which a Main drive faces once started from zero speed. It can have a multiple factor (up to 6 times) of rated current during starting procedure over a certain time period. Regular experiencing of high inrush current can cause motor damages, voltage dips in the supply line (which can consequently affect other equipment) and interrupt the proper Main drive start. Furthermore, the higher level HV grid has to be designed and protected for these cases.
The Inrush current is physically inevitable, but you can choose one of the most minimizing solutions with SETCON: www.set-solutions.net/setcon