LEM LA 205-S Closed-Loop Hall Effect Current Sensor

LA 205-S Product Overview

The LA 205-S is a high-precision current sensor based on closed-loop Hall effect technology, from LEM (Switzerland), the global leader in electrical measurement. Featuring closed-loop (compensated) Hall effect principle, it is designed for electronic measurement of DC, AC, and pulsed currents, with galvanic isolation between the primary and secondary circuits.

The sensor operates on a ±12V ~ ±15V bipolar supply, with a rated current of 200A, a measuring range of ±300A (1.5x overload capability), and a maximum instantaneous overload of 600A. It outputs a 100mA current signal with a turns ratio of 1:2000. It features a 22.7×17.4mm rectangular aperture for easy busbar passage.

With panel mount design, its insulating plastic case complies with UL 94-V0 flame retardant rating. The operating temperature range is -10℃ ~ +85℃, and the standard industrial version features a Molex 5046 4-pin connector for output.

With ±0.8% high accuracy, <0.1% linearity, <1µs response time, and 100kHz bandwidth, the LA 205-S complies with EN 50178 industrial safety standards, making it a classic choice for high-current monitoring in industrial VFDs, UPS systems, welding equipment, and more.

LA 205-S Key Technical Specifications

LA 205-S Key Advantages

Closed-Loop Hall Technology: Active compensation design eliminates core saturation effects — accuracy ±0.8%, linearity <0.1%

<1µs Fast Response + 100kHz High Bandwidth: Response time <1µs, reaction time <500ns, di/dt following >100A/µs — perfectly matched for high-frequency IGBT/PWM switching applications

±300A Wide Range + 600A Overload Capability: 3x rated overload withstand capability — handles motor starting and load transient current surges

Superior Noise Immunity: Closed-loop architecture provides high external magnetic field rejection — stable operation in complex industrial EMI environments such as VFDs and high-power drives

6kV High-Voltage Isolation + 18kV Impulse Withstand: Reinforced insulation between primary and secondary — EN 50178 compliant — meets 3250V reinforced insulation requirements

22.7×17.4mm Large Aperture + Panel Mount: Easy busbar passage — Molex standard connector — convenient and reliable installation

5-Year Factory Warranty: LEM quality commitment — long-term supply assurance

Why Choose the LA 205-S?

±0.8% High Accuracy + <0.1% Linearity: Closed-loop compensation ensures accurate measurement across the full range — meets industrial precision control requirements

<1µs Fast Response: Accurately captures IGBT switching transients and current spikes during load changes — provides timely and reliable triggering signals for overcurrent protection

100kHz High Bandwidth: Accurately measures current waveforms up to 100kHz — perfectly matches the output characteristics of modern high-frequency switching power supplies and VFDs

6kV High-Voltage Isolation: Reinforced insulation between primary and secondary — EN 50178 compliant — suitable for 600V reinforced insulation and 1700V basic insulation scenarios

-10℃~+85℃ Wide Temperature Operation: Covers common industrial field temperature ranges — meets most industrial equipment requirements

Low Power Design: Current consumption only 20mA — reduces power supply burden

Panel Mount Design: 2 × φ5.5mm mounting holes, M5 screw installation — fits various industrial cabinet layouts