LEM LA 306-S Closed-Loop Hall Effect Current Sensor

LA 306-S Product Overview

The LA 306-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 ±15V bipolar supply, with a rated current of 300A, a measuring range of up to ±700A (2.3x overload capability), and a 150mA current output. It features a 30×13mm rectangular aperture for easy busbar passage. With a wide operating temperature range of -40℃ ~ +85℃, its insulating plastic case complies with UL 94-V0 flame retardant rating.

As a core model of the LA306 series, the LA 306-S delivers 0.7% high accuracy, <1µs response time, and DC~50kHz bandwidth — offering closed-loop Hall technology performance at an attractive price. Backed by a 5-year factory warranty, it is an ideal choice for VFDs, power supplies, renewable energy, and other industrial applications.

LA 306-S Key Technical Specifications

LA 306-S Key Advantages

Closed-Loop Hall Technology: Active compensation design eliminates core saturation effects — accuracy ±0.7%, linearity ±0.1%

<1µs Fast Response + 50kHz Bandwidth: Response time <1µs, bandwidth DC~50kHz — accurately captures high-frequency PWM switching current waveforms

±700A Wide Range: 2.3x overload capability — handles current surges during motor starting and load changes

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 + UL 94-V0 Flame Retardant Case: Reinforced insulation between primary and secondary — compliant with EN 50178 industrial safety standards

30×13mm Large Rectangular Aperture: Easy busbar passage — panel mount design — fits various industrial cabinet layouts

-40℃~+85℃ Wide Temperature Range + 5-Year Warranty: Covers applications from cold outdoor to high-temperature industrial environments — LEM quality commitment with 5-year warranty

Molex 5045 Standard Connector: Standardized interface — fast and convenient wiring — reduces installation costs

Why Choose the LA 306-S?

0.7% High Accuracy + 0.1% Linearity: Closed-loop compensation technology 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

50kHz Bandwidth: Accurately measures current waveforms up to 50kHz — perfectly matches the output characteristics of industrial VFDs and switching power supplies

6kV High-Voltage Isolation: Reinforced insulation between primary and secondary — EN 50178 compliant — meets 500V reinforced insulation and 1000V basic insulation requirements

-40℃~+85℃ Wide Temperature Operation + Low Drift: Maximum offset temperature drift only 500µA — suitable for outdoor enclosures, industrial field environments, and other harsh temperature scenarios

30×13mm Rectangular Aperture + Compact Panel Design: Height only 56mm — easy busbar passage — saves cabinet space

Highly Competitive Price: Closed-loop Hall technology performance at an attractive price — a cost-effective choice for industrial high-current monitoring