MotorShield (MSD) sine wave filter greatly extends motor and cable life from harmful VFD PWM drives. UL Listed Type 1/3R, Open UL 508 good for up to 15,000ft. cable leads. a 3-phase low-pass sine wave filter designed and developed by TCI to deliver conditioned power to motor loads driven by PWM drives with switching frequencies from 2 kHz to 16 kHz. Any drive control parameter which has the effect of reducing the carrier or switching frequency below 2 kHz at any time must be disabled. Some sine wave or long lead mode drive parameters or operating modes can have this effect. This filter is suitable for VFD drives configured to Volts per Hz modes only. Available for three phase voltage systems up to 460/480 Volts, the MotorShield™ is a passive LC filter connected in series with the output terminals of the variable frequency drive. This design removes the carrier frequency distortion from the output voltage waveform resulting in a nearly pure sine wave voltage profile. The MotorShield™ sine wave filter reduces the effects of the reflected wave phenomenon (dV/dt), which can cause motor heating, insulation damage, and excessive audible noise. The reduction of high frequency VFD output currents extends the life of motors and transformers and eliminates the need for special motor cables. The MotorShield™ reduces VFD ground fault problems and noise interference in transducer signals caused by stray high frequency harmonic currents.