Line Reactor Calculator: Calculate Voltage Drop & Impedance

    Created by Md jony islam

    3-phase line reactor calculator

    Compute Vdrop, reactance, and impedance of the reactor in AC (alternating current) circuits. Applicable to VFDs, motors, and power systems that employ kVA, voltage, and % impedance. The Line Reactor Calculator aids in the estimation of the reactance and voltage drop across a reactor applied in erring circles. Placing in the frequency of the system, line current, and line inductance, the tool can determine the voltage drop and impedance based on standard formulas of AC. It is particularly handy in the design of VFD and to protect attached motors against voltage transients, harmonics, and surge currents.

    line reactor voltage drop calculator

    Line Reactor Calculator

    Learn how we tools this below

    Add this tools to your site

    Buy me a for Source Code

    What do you need to know to calculate Line Reactor?

    🙋 Try our Slip Speed Calculator . If you want to learn more about conversions using Electrical Engineering Project Calculators.

    line reactor reactance calculator

    Conversion using the Line Reactor Calculation Formula:

    Reactance: X = 2 × π × f × L

    Voltage Drop: V = I × X

    Frequently Asked Questions - Line Reactor Conversion FAQs:

    What is the formula for reactor calculation?

    The reactor calculation is quite commonly based on the use of the reactance formula for the inductors that is XL=2πfLXL​=2πfL, where XL​ represents the inductive reactance (in ohms), also denoted as XL​, ff – the frequency (in Hertz units), L – the inductance (in henries). This formula goes to find the impedance of the reactor used in electrical systems, especially in current limiting or harmonic filtering.

    What is the difference between 3% and 5% line reactors?

    3% and 5% line reactors differ primarily by their impedance rate, which affects the voltage drop and short-circuit current limiting. A 3% reactor has lower impedance than a 5% reactor and, therefore, passes more current when a fault condition occurs. The lower a Reactor’s impedance, the better protection it offers against overcurrent and voltage spikes. The selection of one or another reactor depends upon the particular needs of the electrical system.

    What is the rating of current limiting reactor?

    A typical current-limiting reactor is rated by inductance and impedance. The rating may be 3% to 10% and more, depending on the application. Such reactors are formulated to reduce fault current through the induction of reactance, thereby diminishing the effect of short-circuited circuits in such power systems. It all depends on what fault current level it is designed to accommodate, as well as the specifications of the system.

    Why are line reactors used with VFDs?

    Line reactors are employed together with VFDs to protect against voltage transients as well as to reduce harmonic distortion and limit inrush current. They are inductive buffers between the power source and the drive, which not only increases the power factor but also increases the life of sensitive electronic parts. Line reactors also reduce nuisance tripping and electromagnetic interference (EMI) on motor control systems.

    How do you select a line reactor for a system?

    The choice of line reactor depends on system voltage, current rating, and required percent of impedance (usually 3% or 5%). Important parameters are VFD rating (kW or HP), line voltage (e.g, 400V, 480V), and the THD level of the system. The reactor should match the drive’s continuous current and rated for the correct insulation class and temperature rise for reliable operation.

    About the Author

    Md Jony Islam

    Md Jony Islam: Multidisciplinary Engineer & Financial Expert:

    Md. Jony Islam is a highly skilled professional with expertise in electronics, electrical, mechanical, and civil engineering, as well as finance. Specializing in transformer service and maintenance for 33/11kV substations, he ensures reliable and efficient electrical systems. His mechanical engineering skills drive innovative designs, while his financial acumen supports effective project budgeting. With a strong foundation in civil engineering, he contributes to robust infrastructure development. Md. Jony Islam's multidisciplinary approach ensures efficiency, quality, and reliability across all projects.