Designed for non-intrusive and isolated nominal measurements of DC, AC and pulsed currents from 100 to 2000A, four series of transducers have been released by LEM. The company have developed a way in which to make Hall effect technology realise the performance achieved by fluxgate technology, resulting in an ASIC based on Hall effect technology for use in closed loop mode.
LEM’s spinning technique and specialist ICs have also contributed to these improvements. The LF 210-S, LF 310-S, LF 510-S and LF 1010-S transducers are the first devices to utilise the Hall effect technology. Compared to the previous generation of Closed Loop Hall effect current transducers, the LF xx10 transducers deliver up to four times greater global accuracy over the temperature range (from 0.25 to 0.6% of IPN), with a maximum offset drift of 0.1% of IPN.
While lowering cost, the fluxgate technology allows customers to overcome drawbacks such as noise, starting up with primary current and restarting without delay after an overload. The technology also provides customers with increased control and system efficiency.
The devices operate from a dual supply voltage of ±12 to ± 24V. Due to the magnetic core and winding design, the LF xx10 transducers can measure three times the primary nominal current (LF 510-S model) when responding faster against a di/dt step with a response time of less than 0.5µs. Compared to the previous generation, the LF xx10 range has a low sensitivity to external AC and DC fields, enabling easy product layout in harsh environments applications, as it is not affected by fields created by other components close by.
Fully compatible with the previous LEM LF xx05 range, the transducer range fits into the same footprint and can, therefore, be easily retrofitted into old installations. Without compromising on the high insulation level provided between the primary and measurement circuits, the LF xx10 range can continue to offer various compact sizes for each current range and a variety of panel mounting topologies (flat or vertical).
The LF xx10 transducers are suitable for applications such as variable speed drives, servo motor drives, uninterruptible and switch-mode power supplies, which integrate a higher number of transducers due to the high levels of control and automation that improve productivity and energy efficiency. The transducer range operates from 40 to +85°C, making it suitable for use in industrial or traction applications.
Conforming to the EN 50178 and EN 50155 standards, the LF xx10 range is CE marked and offered with a five-year warranty.