LEM LF305-S/SP6 Closed-Loop Hall Effect Current Transducer

LF305-S/SP6 Product Positioning: Premium Industrial-Grade Precision Current Measurement

The LF305-S/SP6 is a high-performance closed-loop Hall effect current transducer from LEM’s LF series. With a rated current measurement capability of 300 A and support for bidirectional current measurement, this Swiss-engineered device delivers exceptional reliability. It is widely used in industrial automation, railway traction, energy management, and precision testing – fields where high accuracy current measurement is critical.

LF305-S/SP6 Key Highlights: Reliability Driven by Technical Excellence

300 A rated current / 600 A peak measurement range – covers high-power scenarios with ease
±0.1% linearity / ±0.47% accuracy – professional precision
1 µs response time / DC to 100 kHz bandwidth – capture every current transient
-10°C to +70°C operating temperature / low thermal drift – stable even in harsh environments
Fully electrically isolated / UL94-V0 flame-retardant housing – multi-dimensional system safety

LF305-S/SP6 Technical Specifications

LF305-S/SP6 Typical Applications: From Industrial to Railway – Full Scenario Coverage

Industrial automation & drive control
In AC variable speed drives, servo motor drives, and DC motor static converters, the LF305-S/SP6 delivers precise current feedback, helping optimise drive performance and extend equipment life.

Power supplies & energy management
In uninterruptible power supplies, switchmode power supplies, and battery management systems, the transducer accurately measures charge/discharge currents to ensure safe and stable operation.

Welding equipment & railway traction
Provides accurate current measurement in welding power sources to guarantee welding quality; plays a key role in railway traction system inverters and brake choppers.

Precision testing & new energy
Ideal for laboratory precision measurements, renewable energy system monitoring, and current detection in EV charging and drive systems.

Five Technical Advantages: Why Choose the LF305-S/SP6

Closed-loop Hall effect – superior to open-loop.
Unlike open-loop transducers, closed-loop technology dynamically balances the magnetic flux in the core with a secondary compensation winding. This greatly improves accuracy, linearity, and response time, maintaining consistently high measurement performance across the full frequency range.

Low thermal drift – no performance compromise over wide temperature range.
The LF series exhibits excellent low-drift characteristics over a wide temperature range, maintaining high precision even under fluctuating thermal conditions – meeting the long-term reliability requirements of harsh industrial environments.

High immunity to interference – operates with confidence in electromagnetically noisy environments.
Strong resistance to external electromagnetic interference ensures accurate current measurement even in industrial and railway applications with complex EMC conditions.

High overload capability – handles transient currents.
Wide bandwidth and high current overload capability allow the transducer to manage sudden current fluctuations in the system, effectively protecting downstream circuits.

Swiss made – quality you can trust.
LEM is a world leader in current sensing with decades of experience. The LF305-S/SP6 is manufactured in Switzerland. Its lightweight 100 g design combines miniaturisation with robust performance.