Sine wave filtering for 600VAC and 690 VAC drives

March 18, 2013 // By Graham Prophet
For industrial-drive designers working with 690VAC and 600VAC motor applications, Schaffner has introduced the FN5040HV series of sine wave filters. In combination with variable speed drives, the filters can extra losses in the AC motors, and also help to extend the motor life time.

They are suited to applications where the motor cables (from inverter to motor) are long. The filters occupy an open compact frame, and smooth the rectangular PWM output voltage of modern drives to provide the motor with a sine wave voltage with low residual ripple of under 5%. This largely reduces premature ageing or destruction of the AC motor due to high dv/dt, over-voltages, bearing currents or overheating due to extra losses. Expensive downtime, premature service and maintenance costs can be reduced. FN5040HV sine wave filters are available in 14 current ratings between 13 and 1320A and are specified for typical network supplies of 3x690VAC and 3x600VAC for up to 1,200kW of drive power. Drives delivering higher powers most often employ lower switching frequencies to minimise the power losses. Schaffner’s sine wave filters are designed to operate at 1.5kHz for drives of over 355kW. More at