Line Reactors For VFDs

Line reactors are critical components used on the input side of variable frequency drives (VFDs) to protect against power line disturbances and improve overall system performance. By adding impedance to the incoming power supply, line reactors help limit inrush current, smooth current waveforms, and reduce voltage distortion that can negatively impact drive operation. RSP Supply offers a full range of line reactors for VFDs with impedance ratings up to 10% to support a wide variety of industrial applications.
During high-demand operating conditions such as motor startup or rapid acceleration, excessive inlet current can place stress on the VFD’s power electronics. Line reactors help stabilize current flow, preventing nuisance faults and protecting the drive from voltage spikes, transients, and harmonic distortion commonly found in three-phase power systems. This added impedance improves power quality while extending the service life of the VFD.
Installed between the power source and the VFD, line reactors differ from load reactors, which are placed between the drive and the motor. While load reactors protect motors from high-frequency switching effects and reflected wave voltages, line reactors focus on shielding the VFD from upstream electrical disturbances. Line reactors are especially beneficial in facilities with weak power systems, frequent voltage fluctuations, or multiple nonlinear loads.
FAQs
Q: What does a line reactor do for a VFD?
A line reactor limits inrush current, reduces harmonic distortion, and protects the VFD from voltage spikes, transients, and other power line disturbances on the input side.
Q: What is the difference between a line reactor and a load reactor?
A line reactor is installed on the input side of a VFD to protect the drive from power supply issues. A load reactor is installed on the output side to protect the motor from voltage spikes and high-frequency switching effects.
Q: What does 10% impedance mean for a line reactor?
The impedance percentage indicates how much the reactor resists changes in current. Higher impedance provides greater harmonic reduction and current limiting, with 10% impedance offering maximum protection for sensitive applications.
Q: Do line reactors reduce harmonics in VFD systems?
Yes, line reactors help reduce harmonic distortion by smoothing current waveforms and limiting rapid changes in current drawn by the VFD.
Q: Are line reactors used with inductive loads like motors?
Yes, VFD systems commonly drive inductive loads such as motors, pumps, and fans. Line reactors help manage the electrical characteristics of these systems by stabilizing current and voltage at the VFD input.
Why Buy Line Reactors from RSP Supply
RSP Supply offers a comprehensive selection of line reactors for VFD applications, including models with impedance ratings up to 10%. Our products support improved power quality, drive protection, and long-term system reliability. Customers rely on RSP Supply for trusted manufacturers, technical expertise, and dependable solutions for industrial motor control and power conditioning needs.