Motors and Drives: Variable Frequency Drive (VFD)--Accessories
Part 8 of the Variable Frequency Drives Series explores accessories to protect variable frequency drives.
Input Fuses – Protect drive from excessive input current from line surges short circuits, ground faults. Recommended and may be required for UL installations
Line Reactors – Protects the drive from transient overvoltages (utilities switching), reduces input harmonics
EMI Filters – (ElectroMagnetic Interference Filter) reduces noise on the input side of the drive (required for CE applications). Drives are ONLY marked CE because they are used with these filters . Help prevent noise radiation to sensitive adjacent equipment.
RF Filters – aka Zero Phase reactors help reduce the noise radiated from the VFD wiring on the output side.
Braking Resistors – Needed to burn off excessive energy induced to the DC bus due to Back EMF during stopping.
Encoder Feedback Cards – Needed for better speed regulation and control