WESTEK Electronics has released the MTE Series A dv/dt filters, designed to protect ac motors from the destructive effects of peak voltages typical of long cable runs between the inverter and motor.
The MTE dv/dt filter meets its maximum peak motor voltage specification (150% of bus voltage) with up to 300m of cable between the filter and the motor. It is also rated for a maximum dv/dt of 200V/μs. In specific applications, the filter has provided excellent performance with cable runs up to 900m. The filter has a 3% insertion impedance, which ensures motor torque is not affected by added voltage drops from the filter. It is designed for use with inverters operated at switching frequencies between 900Hz and 8kHz. It has a continuous current rating of 100% rms and intermittent current of 150% for one minute and 200% for 10 seconds.
The filter is available as panel-mount or in NEMA 1, 1-2 and 3R enclosures. It is rated for use in temperatures up to 50°C as panel mount or 40°C with enclosed cabinets. Typical applications include submersible pumps, HVAC equipment and process automation lines.
Motors rated 75kW and below and standard NEMA B motors, MG1Part 30, are prone to failure as a result of high voltage spikes and will benefit from dv/dt filtering. The MTE dv/dt filter is UL and cUL-listed to UL508 and CSA-C22.2 No 14-95 File E180243 (2.25kW-750kW, 120V ac through 600V ac 50. 50Hz/60Hz three phase).