HTFS 400-P/SP2 Open Loop Hall Effect Current Sensor | In Stock, Authorized LEM Distributor

HTFS400-P/SP2 Accurate Monitoring, Reliable Protection – The Ideal Choice for High-Current Industrial Measurement

In variable frequency drives, power supplies, and renewable energy systems, the accuracy of highcurrent measurement directly affects overall system safety and efficiency. Choosing the wrong current sensor can lead to measurement errors or, worse, cause overload protection failures that create safety hazards.

HTFS 400-P/SP2 is a flagship PCB-mount open-loop Hall effect current sensor from LEM (LEM Group) of Switzerland. As a world leader in electrical transducers, LEM brings over 40 years of expertise and innovation to deliver reliable, highperformance solutions for harsh industrial environments. This model offers a rated primary current of 400A and an extended measuring range up to ±600A.

HTFS400-P/SP2 Key Features: More Than High Current – High Precision Too

LEM’s Proprietary ASIC Technology – 1% Class Accuracy
Using LEM’s own ASIC (Application-Specific Integrated Circuit) combined with open-loop Hall effect technology, the sensor achieves ±1% accuracy at room temperature and ±0.5% linearity. Even in electromagnetically noisy environments, the output signal remains reliable, enabling precise regulation and fault prediction in your system.

Fast Response – Microsecond Capture of Dynamic Current
Response speed is critical when dealing with transient short-circuit currents or complex pulse waveforms in power electronics. HTFS 400-P/SP2 provides a fast response time of 3.5µs (typical) and a bandwidth from DC to 50 kHz. It accurately captures not only steady-state DC/AC signals but also transient pulses and mixed waveforms, ensuring your protection circuit always stays ahead.

Fully Isolated Primary to Secondary – High-Voltage Safety
The sensor provides galvanic isolation between the high-power primary circuit and the low-power secondary measurement circuit, with a dielectric strength test voltage of 2.5 kVrms. This significantly enhances safety for operators and downstream electronics.

Wide Operating Temperature – Stable in Extreme Environments
Whether in cold northern winters (-40°C) or hot, crowded equipment cabinets (+105°C), HTFS 400-P/SP2 operates reliably. Its large 22mm primary aperture allows the conductor to pass through, optimising heat dissipation and avoiding heat buildup under high current.

SP2 Enhanced Version – Robust PCB Solder Fixation
The “SP2” suffix means the sensor uses four 1mm-diameter solder pins for PCB mounting. Compared to traditional screw-type terminals, the SP2 version offers superior vibration resistance and longterm electrical contact reliability, making it ideal for applications such as electric vehicles and heavy machinery.

HTFS400-P/SP2 Technical Specifications

Brand: LEM (LEM Group) / LEM USA Inc.

Rated Primary Current: 400A (measures AC+DC mixed signals)

Measuring Range: ±600A max.

Output Type: Ratiometric voltage output (Vcc/2 ± 1.25V @ 600A)

Supply Voltage: Single +5V (4.75V ~ 5.25V)

Accuracy / Linearity: ±1% / ±0.5%

Response Time: < 7µs (3.5µs typical)

Bandwidth: DC ~ 50 kHz

Aperture Diameter: 22 mm (primary conductor passes through)

Operating Temperature: -40°C ~ +105°C

Mounting Type: PCB-mount, 4-pin solder (SP2 enhanced)

Isolation Test Voltage: 2.5 kV / 50Hz / 1 min

Compliance: RoHS, EN50178 industrial safety standards

HTFS400-P/SP2 Key Applications – Power Your Industrial Innovation

HTFS 400-P/SP2 is more than a sensor – it is a guardian of your equipment’s performance:

Renewable Energy & Storage: solar inverters, battery management systems (BMS), EV charger current monitoring.

Industrial Drives & Control: AC servo drives, VFDs, DC static converters, hoisting equipment.

Power Supplies & Welding: high-power SMPS, welding machine current feedback and control.

Specialty Vehicles: forklifts, electric golf carts, electric wheelchair power system monitoring.

Heavy Industry & Metallurgy: high-current continuous monitoring in oil & gas extraction and metal smelting.