PSR Soft Starter This range covers motor currents from 3 to 45A. With their compact design, the PSR Soft Starters are ideal for installations in places where space is limited and where there is a demand for easy installation. All sizes include a run signal relay, while sizes from 25A are also provided with an output signal for TOR (Top of Ramp), i.e. Full Voltage. With standard performance the PSR Soft Starters handle 10 starts per hour. When an auxiliary fan is added, the starting capacity is increased to 20 starts per hour.