LT4000-S/SP45 – Closed-Loop Hall Effect Current Sensor for High-Accuracy Large Current Monitoring

LT4000-S/SP45 Time to Upgrade Your High-Current Measurement Solution

In today’s high-power systems where energy efficiency and safety are paramount, accurate current monitoring is critical. Traditional open-loop Hall sensors or shunts often suffer from non-linearity, significant power loss, and troublesome temperature drift, making them unreliable under high dynamic response and large current surges.

LEM, the global leader in electrical measurement founded in Geneva, Switzerland in 1972, introduces the LT4000-S/SP45 closed-loop Hall effect current sensor – designed to solve the core pain points of large-current, low-impedance systems. It is far more than a simple current transformer; it’s an advanced current measurement solution based on Hall technology, delivering exceptional control accuracy and long-term stability.

Key Performance Specifications

Genuine LEM product – engineered for high-precision measurement of large currents:

Model： LT4000-S/SP45

Primary rated current： 4400 A (provides extra safety margin)

Current measurement range： 12000 A (excellent overload capability, handles transient surges)

Accuracy： 0.2 % – industry leading standard for precision control

Technology： Closed-loop Hall effect

Output signal： Current output 880 mA (instantaneous)

Supply voltage： Bipolar ±15 to ±24 V

Operating temperature： -25℃ ~ +70℃ (suited for harsh industrial environments)

Insulation： Galvanic isolation between primary (high power) and secondary (electronic) circuits

Why Choose the LT4000-S/SP45? – 6 “Hard-Core” Advantages

In motor drives, rail traction, or high-power supplies, safety and efficiency translate directly into profit. The LT4000-S/SP45 becomes your most reliable guardian with these features:

Excellent Linearity and Low Temperature Drift

Say goodbye to data distortion caused by high ambient temperatures. With extremely low temperature drift, the LT4000-S/SP45 maintains 0.2% linearity across its full range, delivering accurate current readings even at -25℃ or +70℃.

High Current Capability with No Measurement Loss

Measures up to 4400 A continuously and up to 12000 A without saturation. The very low resistance of the primary conductor virtually eliminates heat losses – no more overheating of the sensor itself; the power you save is visible profit.

High Dynamic Response of Closed-Loop Hall Technology

Advanced closed-loop compensation enables fast response time and a bandwidth up to 100 kHz. Whether it’s instantaneous overcurrent in a servo drive or a surge in a power supply, the LT4000-S/SP45 reacts instantly, providing critical protection time for your valuable equipment and preventing false PLC alarms.

Strong Immunity to Electromagnetic Interference

EMI in industrial environments is a common culprit for inaccurate measurement. The LT4000-S/SP45 features electrostatic shielding and an insulating plastic housing (UL 94V0 rated) – not only flameretardant but also highly immune to external interference, keeping your communication and control systems clear-sighted.

Large Primary Aperture

We know how difficult busbar routing can be. The LT4000-S/SP45 offers a 102 mm diameter through-hole. Whether thick copper bars, insulated cables, or multiple twisted pairs, installation is easy even in tight spaces.

Swiss Precision – Rugged & Durable

As a Swiss company founded in 1972 and listed on the SIX Swiss Exchange, LEM uses modular panel-mount packaging. The sensor withstands heavy industrial vibration and extreme temperature variations (storage temperature from -40℃ to +85℃).

LT4000-S/SP45 Diverse Application Scenarios

Whether you are a design, procurement, or maintenance engineer, the LT4000-S/SP45 will become an indispensable precision partner:

Industrial Automation – Large AC variable speed drives, CNC spindle drives – ensures torque control and motor safety.

HighPower Power Supplies & UPS – Overcurrent detection and short-circuit protection in UPS and SMPS, keeping data centers safe.

New Energy & Battery Power – Large battery charge/discharge management, BMS for energy storage systems.

Welding & Special Power Supplies – Accurate pulse current monitoring for inverter welders, improving weld quality.

Traction & Rail Transit – Excellent insulation voltage characteristics, ideal for industrial, railway, and heavy-duty truck power management systems.