LEM LT 100-S/SP30 Closed-Loop Hall Effect Current Transducer

LEM LT 100-S/SP30 Product Overview

The LT 100-S/SP30 is a closed-loop Hall effect current transducer from LEM's LT 100 series, designed for electronic measurement of DC, AC, and pulsed currents with galvanic isolation between the primary circuit (high power) and the secondary circuit (electronic circuit). It is specifically optimized for traction applications including railway propulsion and braking choppers, traction converters, and auxiliary converters.

The sensor features a compact panel-mount design with a 15 mm diameter aperture for the primary conductor crossing. Secondary connections are made via 3 Faston 6.3×0.8 mm tabs (supply voltage +, measure, supply voltage -), and panel mounting is achieved with 4 M4 screws through Ø4.3 mm holes (recommended fastening torque 3.2 Nm). The case is potted for environmental protection and recognized according to UL 94-V0.

This model is rated for 100 A nominal current with a measuring range of ±200 A, outputting a 100 mA instantaneous current signal with 1:1000 turns ratio. Accuracy is ±0.5% at 25°C, with linearity <0.1% and an overall accuracy of ±0.5%. It operates on a ±12V to ±18V bipolar supply, with a DC~150 kHz bandwidth and a <1 µs response time.

The sensor features a 5 kV RMS insulation test voltage for high-voltage safety. It operates over a temperature range of -40°C to +85°C and is compliant with EN 50155:2001 railway standards. The mass is 180 g.

LEM LT 100-S/SP30 Key Technical Specifications

LEM LT 100-S/SP30 Core Advantages

Closed-Loop Hall Technology with Active Compensation: Delivers ±0.5% accuracy and <0.1% linearity across the full measuring range, eliminating core saturation errors found in open-loop sensors.

±200 A Wide Measuring Range with 2× Overload Capability: The 100 A nominal sensor can measure up to ±200 A peak, providing ample safety margin for traction system transients and fault conditions.

5 kV High-Insulation Withstand Voltage: Provides 5 kV RMS insulation test voltage, ensuring superior safety in railway traction environments.

<1 µs Fast Response + 150 kHz Bandwidth: Captures fast IGBT switching transients and high-frequency current components with >50 A/µs di/dt following capability.

Traction-Grade Design with EN 50155 Compliance: Designed for railway propulsion converters, braking choppers, and auxiliary converters with -40°C to +70°C operating range.

Compact Panel-Mount Design: 180 g lightweight design with 15 mm aperture for easy installation.

Potted Construction for Environmental Protection: Potted case ensures protection against moisture and contaminants in demanding railway environments.

High Immunity to External Interference: Closed-loop compensation design provides excellent rejection of external magnetic fields and common mode noise.

No Insertion Losses: Non-contact Hall measurement adds no energy loss to the primary circuit.

Active Part Status with Full Manufacturer Support: Currently available through distributors with full LEM support.

LEM LT 100-S/SP30 Target Applications

The LT 100 series is specifically designed for traction applications :

Single or three-phase inverters

Propulsion and braking choppers

Propulsion converters

Auxiliary converters

Battery chargers

Railway (fixed installations and onboard)