The typical values measured at a distance of 1 m from the unit:FC 301/ FC 302PK25-P7K5: @ 400 V IP20/IP21/NEMA TYPE 1PK25-P7K5 IP55/NEMA TYPE 12Reduced fan speed 51 dB(A)Full fan speed 60 dB(A)Peak Voltage on MotorWhen a transistor in the inverter bridge switches, the voltage across the motor increases by a dV/dt ratiodepending on:- the motor cable (type, cross-section, length screened or unscreened)- inductanceThe natural induction causes an overshot UPEAK in the motor voltage before it stabilises itself at a leveldepending on the voltage in the intermediate circuit . The rise time and the peak voltage UPEAK affectthe service life of the motor. If the peak voltage is too high, especially motors without phase coil insulationare affected. If the motor cable is short (a few metres), the rise time and peak voltage are lower.If the motor cable is long (100 m), the rise time and peak voltage increases.If very small motors are used without phase coil insulation, connect an LC filter to the frequency con-verter.FC 300 Design GuideFC 300 SelectionMG.33.B7.02 - VLT is a registered Danfoss trademark 59
