LEM is the market leader in providing innovative and high-quality solutions for measuring electrical parameters. Its core products – current and voltage transducers – are used in a broad range of applications including renewable energy and power supplies, drives and welding, traction, high-precision, smart grid applications and the automotive market.

LEM’s innovative technologies provide increased accuracy and speed to ensure a high degree of reliability and safety, enabling smoother control and reducing energy consumption in a wide range of electrical systems.

At the heart of … renewable energy

LEM transducers, specifically designed for renewable power systems, control the flow and waveform of energy sent to the grid from renewable energy systems. They measure the current to help the wind turbines and solar installations to work at their maximum efficiency.

Current transducers are indispensable components in modern wind energy turbines. LEM, with more than 45 years’ experience in the development of transducers, contributes a vast expertise for these applications providing ready-to-use solutions; others can be developed and manufactured to meet the demands of customers and applications.

LEM’s dynamic closed-loop current transducers – models LF 210-S, LF 310-S, LF 510-S, LF 1010-S, LF 2010-S – can be used in both the rectifier and the inverter. They feature good common-mode behaviour as well as an accuracy of 0.2 to 0.6 % (with reference to the rated value) over the temperature range from -40°C to +85°C. By using the closed-loop principle, these fast response transducers provide short-circuit protection of the power semiconductors in the inverters – an invaluable advantage for wind energy turbines in offshore areas where the maintenance is difficult and expensive.

Current transducers also enable current control in the low power electrical drives used for the blade pitch and yaw control allowing optimisation of the power generation and safety against the wind direction. Moulded versions are also available for harsh environments.

At the heart of … traction

Regardless of whether a train is powered by diesel or electricity, traction is provided by electric motors driven by inverters that rely on LEM transducers to measure, optimise and adjust the power that is sent to the motors, improving both performance and reliability.

At the heart of … high precision applications

LEM current transducers set a standard for accuracy and are the most precise industrial products in the market today. The transducers provide levels of stability and precision, at about 1-3 parts per million, which makes them references in calibration test benches or in laboratories.

At the heart of … automotive

In electric and hybrid vehicles, LEM transducers monitor energy levels to and from the battery and are critical for the control of the electric motors.

With more than 2,500 current and voltage transducers in its portfolio, LEM offers a complete range of accurate, reliable, and Galvanically isolated devices for the measurement of currents from 0.25-24,000A and voltages from 10-6400V in various technologies: open loop, closed loop, fluxgate, insulating digital technology, Rogowski, current transformer, et cetera.

LEM transducers are designed according to the most demanding international standards (EN50178, EN 50155, EN50124-1, NFF 16101, 16102, etc.) and carry CE marking. UL Recognition (UR) is also available on most models.

We have worldwide ISO 9001, ISO TS 16949 and IRIS (Geneva, Beijing and Sofia LEM production and design centres) qualification and offer a five-year warranty on all of our products.

LEM is a world-wide company with regional sales offices across the globe close to its clients’ locations and production facilities in Switzerland, Europe (including Russia and Bulgaria) and Asia (China and Japan) for seamless service everywhere.