PRS2DN15¡­840 series is a sort of current-controlled intellectual soft starter newly designed on the basis of PRS2S,PR2D/DH and adopting the most advanced digital processor to regulate voltage. Its unique intellectual electronic circuit provides perfect controlling and protective functions: linearity acceleration start, pump start, pump stop control, preset low voltage operation, preset both of parameters for soft start and soft stop and switch each other freely, monitor load status and automatically change to the light ¨Cload and energy-saving pattern , protective function of testing motor insulation, phase loss, short circuit, protection against over-load etc. With RS 485 and Profibus protocol, which realizes full micro-controller and monitoring.