LTC350-SF/SP5 Closed-Loop Hall Effect Current Transducer – Built for Precision Industrial Measurement

In industrial automation, renewable energy, and rail transportation, the accuracy and stability of current monitoring define the performance limits of the entire system. LEM, a global leader in current sensing technology, presents the LTC350-SF/SP5 closed-loop Hall effect current transducer – a core solution designed for high-precision current measurement in harsh industrial environments.

Why Choose the LTC350-SF/SP5?

Precision comes from closed-loop technology. Unlike traditional open-loop Hall sensors, the LTC350-SF/SP5 uses closed-loop (magnetic balance) Hall effect technology. A secondary coil generates a real-time compensating magnetic field, keeping the net flux in the magnetic core at zero. The result is ±0.5% accuracy and ±0.1% linearity, maintained consistently across the entire -40°C to +85°C temperature range.

Speed makes the professional difference. With a 1 µs response time, the sensor captures current fluctuations almost instantly when load changes or faults occur, providing a critical time window for protection circuits and control systems. Its DC to 100 kHz frequency response accurately captures every detail of DC, AC, and complex pulsed current signals.

Wide range handles extreme conditions. The LTC350-SF/SP5 has a rated current of 350 A and an ultra-wide measurement range of up to 900 A (peak 1200 A). Even with instantaneous large overcurrent events, it continues to output precise measurements without damage or distortion.

LTC350-SF/SP5 Key Technical Specifications

LTC350-SF/SP5 Flexible Mounting to Fit Various Systems

The modular design of the LTC350-SF/SP5 is another highlight. The transducer can be mounted horizontally or vertically, with three mounting options on the base. The busbar can also be installed in two different configurations to suit various cabinet layouts and space constraints. The primary conductor passes through the 27.5 mm aperture – no special adapters needed.

Secondary connections feature a dual fastening design: choose either four M5 threaded studs or four Faston (6.3×0.8 mm) tab terminals, offering flexible and reliable wiring. The sensor is equipped with standard shielding to effectively resist external electromagnetic interference, ensuring a clean output signal.

LTC350-SF/SP5 Main Applications

Electric vehicle charging stations – In 800V high-voltage fast-charging systems, the LTC350-SF/SP5 delivers high accuracy and fast response, precisely monitoring charging current to ensure safety. Field data shows that using this type of sensor improves charging efficiency by 4.2% and reduces fault rates by 37%.

Rail traction systems – The LTC series is specifically designed for traction applications, including main and auxiliary converters, substations, circuit breakers, and charging equipment. It maintains stable operation in harsh electromagnetic and vibration environments.

Industrial robots & servo control – Real-time current monitoring of robot joint motors enables fast fault diagnosis, reducing response time from 20 ms to 5 ms.

Photovoltaic & energy storage systems – With ±0.5% high-precision current measurement in inverters, renewable energy plants can accurately calculate generation efficiency, detect anomalies early, and avoid equipment losses.