Litz wire—derived from the German word Litzendraht (meaning woven or stranded wire)—is an engineered conductor composed of multiple individually insulated strands twisted or braided together in uniform patterns. It is specifically designed to mitigate high-frequency electrical losses in electromagnetic winding applications such as motors, transformers, and inductors.
In direct current (DC) circuits, electrical current flows uniformly through the entire cross-section of a solid conductor. However, in alternating current (AC) applications—especially as operating frequencies climb into tens or hundreds of kilohertz—alternating magnetic fields push the current toward the outer perimeter of the conductor. This phenomenon, known as the skin effect, leaves the center of a solid copper wire virtually non-conductive, drastically reducing its effective cross-sectional area and causing alternating current resistance ($R_{AC}$) and thermal losses to soar.
By utilizing individually insulated, enamel-coated fine wire strands transposed in precise geometric layouts, Litz wire ensures that current distributes evenly among all strands. This construction neutralizes both the skin effect and proximity effect, significantly improving energy efficiency and maximizing conductive copper utilization within tight winding windows.
Litz wire constructions are classified into six distinct round configurations (Types 1 through 6) and two compacted, formed profiles (rectangular or square shapes, Types 7 and 8) to maximize fill factor.
Key Technical Takeaways
- Enamel Insulation: Every individual strand is coated with a thin dielectric enamel film to prevent strand-to-strand electrical conduction.
- Skin Effect Mitigation: Prevents high-frequency AC current from concentrating solely on the outer perimeter of the conductor, maximizing active conductive area.
- Increased Winding Efficiency: Drastically reduces $R_{AC}$ losses and thermal generation in high-frequency motors, inverters, inductors, and transformers.
- Construction Versatility: Manufactured in six standard round types and two formed/compacted profiles (square and rectangular) for optimal slot fill factor.
- Broad Customization: Strand counts, wire gauges (AWG), enamel formulations, and outer textile servings are tailored to specific target operating frequencies.
Episode Transcript – Introduction to Litz Wire
What is Litz Wire?
Litz wire is wire that’s insulated with a thin enamel-type coating that seeks to mitigate electrical losses in high-frequency winding applications. Winding applications are things like motors and transformers that attempt to maximize the use of the conductive material in the winding area.
High-Frequency Losses and the Skin Effect
Customers usually operate these devices at high frequency. As the frequency increases, the current tends to move to the skin of the conductor, making the center of the conductor almost useless.
Round and Formed Construction Types
There are six different round types of constructions and two formed types of constructions. NEWT can handle them all.
