Semiconductor soft starter 3RW3 Settings The units offer the following setting possibilities: 3RW30 The following can be set by means of 3 potentiometers: Starting time within the range from 0 to 20 sec. Starting voltage within the range from approx. 30 to 100% of the rated motor voltage Coasting time within the range from 0 to 20 sec. 3RW31 The following can be set by means of 3 potentiometers: Starting time 1 within the range from 0 to 20 sec. Starting voltage within the range from approx. 30 to 100% of the rated motor voltage Starting time 2 within the range from 0 to 20 sec. A special software ensures setting of progressive ramp times. Short times of up to 5 sec.
can therefore be et very exactly. Auxiliary contacts 3RW30 The following auxiliary contacts are integrated in sizes S0 to S3: "ON": when triggered, the latching signal is used for locking by way of a simple "On" and "Off" pushbutton (contact designation 13/14) "BYPASSED": with the starting end signal, control valves can be addressed after soft starting of a pump, for example, in order to enable conveying (contact designation 23/24) The size S00 units do not have any auxiliary switches. 3RW31 The 3RW31 does not have any auxiliary contacts. Soft starting function Torque-reduced starting for three-phase asynchronous motors:
By two-phase cycling, the current is kept at low values during the complete starting time. Current spikes, as are encountered during star-delta switch- ing, are prevented by continuous voltage influencing. Transient current spike (inrush currents) are avoided automatically by the special cycling function of the power semiconductors during each power-on cycle. Soft coasting function Abrupt stopping of the drive on deactivation of the motor is avoided by the integrated soft coasting function. Time ramps 3RW30 The following graphics show the time ramp of the 3RW30 and the timing diagram of the auxiliary contacts : U N U s t R on t R off t R on t R off 3RW30:
Time ramp Time diagram of the auxiliary contacts Fig. 8-7: Ramp/timing diagram, 3RW30 Rev. 08/99 8-11 U t ON 13/14 BYPASSED 23/24