While soft starters and variable frequency drives are similar in nature, the latter offers many more features in addition to just the ramp up to full speed that a soft starter offers. A VFD allows for adjusting the torque or power of a motor to extend its life span, for adjusting the speed to match the application and finally it saves energy and improves the systems efficiency. The ability of these units to match the energy requirement of the motor or equipment is what sets VFD's apart from any other motor control solution.
Whether you need a simple 5 horsepower drive rated for 230 volt or a more robust 75 horsepower drive rated for 460, Benshaw offers a VFD suitable for your application. Their RSI series has an offering from 1 to 5 H.P. in a protected chassis NEMA 1 enclosure up to 700 H.P. @ 460 volt for the SG series. Should your requirements be for an engineered enclosed VFD, Benshaw has numerous options, including the RX2E and RX3E series of severe duty variable frequency drives that are offered in NEMA 12 and NEMA 3R enclosures for outdoor use.