LT505-S/SP35,LT 505-S/SP35

LT505-S/SP35 Product Overview: Precision Measurement – Defining a New Standard for Industrial Current Sensing

In automated control systems and high-efficiency energy systems, the accuracy and stability of current measurement directly affect equipment safety and performance. The LT505-S/SP35 is a high-performance closed-loop Hall-effect current sensor from LEM – a globally recognized leader in sensor technology. Following the well-proven LT series design, this sensor is specifically built for precise measurement of DC, AC, and pulse currents in demanding industrial and power applications.

As a leading name in current sensing, LEM’s products are widely trusted for their exceptional closed-loop Hall technology and insulated plastic housing design. The LT505-S/SP35 not only offers outstanding overall accuracy of ±0.6% and a linearity error of ±0.1%, but also exhibits very low thermal drift over a wide temperature range. With a bandwidth up to 150 kHz, it accurately captures fast-changing current signals. Whether used in variable-frequency drive power monitoring, renewable energy conversion, or servo drive current control, this sensor delivers excellent performance.

LT505-S/SP35 Key Specifications: High-End Features at a Glance

LT505-S/SP35 Technical Explanation: Core Specifications Decoded

Rated 500 A, can measure up to 1200 A – For transient pulse currents or inrush overloads, the wide measuring range of the LT505-S/SP35 avoids early saturation or damage, perfectly handling surge impacts in power systems.

µs-level fast response – For overcurrent protection in inverters or photovoltaic systems, the short current spikes during IGBT turn-off are fleeting. With a response time ≤1 µs, the LT505-S/SP35 captures abnormal signals quickly, giving the control system early warning.

±0.6% high accuracy – While many open-loop sensors achieve only a few percent accuracy, the LT505-S/SP35 delivers accuracy down to decimal points. In precision power quality analysis or high-end welding equipment, this directly translates into improved control efficiency.

Why Choose LT505-S/SP35? Six Core Advantages Explained

Closed-Loop Hall Technology: Guarantee of Accuracy and Linearity
The reliability of the sensor determines the reliability of the entire system. The LT505-S/SP35 uses a closed-loop Hall compensation structure. Unlike openloop designs that are susceptible to temperature drift and external magnetic fields, the closed-loop configuration generates a compensation magnetic field via a secondary coil to cancel the flux from the primary current, achieving near-zero core flux. This results in very stable output over the full temperature range, excellent linearity (≤±0.1%), and superior frequency response – ideal for control loops that demand high-accuracy current feedback.

Excellent Linearity and Very Low Temperature Drift
±0.1% linearity means the sensor reproduces the true waveform with an almost perfect linear relationship over the entire measuring range, avoiding signal distortion. Meanwhile, the very low temperature drift ensures stable readings even during prolonged operation, eliminating the need for extra software calibration to compensate for sensor heating.

Full Galvanic Isolation for Safety
The LT505-S/SP35 creates a robust isolation barrier between the high-power primary side (energy bus) and the control circuit (electronic circuitry). Even if a surge or short circuit occurs on the power side, downstream equipment such as PLCs, data acquisition modules, or instruments remain safe. The insulated housing meets UL 94-V0 safety standards – a valuable asset for industrial safety compliance.

Zero Insertion Loss
Traditional shunts generate significant heat when measuring large currents, requiring bulky heat sinks. By contrast, the sensor uses passive magnetic-to-electric conversion without any insertion loss on the primary circuit. The sensor itself generates negligible heat and needs no additional heat sinking, simplifying thermal management.

Excellent Immunity to External Interference and Overload Capability
In the harsh electromagnetic environment of variable-frequency drives or motor start/stop cycles, the LT505-S/SP35’s closed-loop architecture offers low output impedance and high common-mode rejection. It delivers stable output signals even under heavy EMI. Moreover, when the primary current exceeds the rated value, the sensor’s built-in overload capability continues to provide reliable measurement, protecting expensive downstream control boards and reducing costly production line downtime.

Premium International Brand – Certification Assurance
LEM is a world leader in current sensing. All LEM devices comply with ROHS3 and ISO9001 quality standards. Choosing the LT505-S/SP35 gives your end product a strong foundation for international certifications and safety reviews, making it easier to pass tenders and project acceptance tests.

LT505-S/SP35 Typical Applications: Supporting Industry, Energy and Automation

Beyond excellent specifications, the LT505-S/SP35 excels in a wide range of realworld applications:

AC variable speed drives and servo motor drives – Real-time current loop monitoring improves torque control accuracy for smoother operation of machine tools, printing equipment, etc.

Uninterruptible power supplies & switch-mode power supplies (UPS & SMPS) – Monitor input/output current and provide instantaneous overcurrent protection during power fluctuations, ensuring uninterrupted operation of data centers and medical equipment.

Solar inverters and energy storage systems – High-precision DC and AC current measurement allows accurate tracking of MPPT (Maximum Power Point Tracking) efficiency.

Static converters for DC motor drives – Stable DC-link current improves energy efficiency for subway ventilation fans and heavy lifting equipment.

Welding equipment power supplies – Precision welding is highly dependent on stable welding current. This sensor works with the control system to provide ripple-free energy.

Comparison: LT505-S/SP35 vs. Standard LT505S