Danfoss dV/dt Filters

Danfoss dV/dt filter technology enable non-inverter duty motors – including older, two-speed motors – to comport with its VFD technology, providing a cost-effective means to reduce the risk of motor failure – by approximately 80%.

“dV/dt” filters provide a slower voltage rise rate on a motor’s terminal phase-to-phase voltage.  The higher the level of inductance, the higher the voltage peaks, which can cause flashover, a condition that results in premature breakdown of the winding insulation of a connected motor.

dV/dt filters reduce the peak voltage, enabling them to prolong the life of a motor.  They accomplish this by cutting off frequencies above the switching frequency.

Similarly, Danfoss “sine” filters eliminate 100% of the risk of applying VFD technology to a non-inverter-duty motor – at a higher component cost.  Ask NES which filter application make sense for your, particular set of circumstances.