Split-Core Transformers measure AC primary currents.

Press Release Summary:

Self-powered TT series features ferrite core material, with magnetic permeability, insensitive to aging and temperature changes. While TT 50-SD (50 A range) measures 1.43 x 1.69 x 1.24 in. and has .31 in. dia sensing aperture for non-contact measurement, TT 100-SD (100 A range) measures 1.75 x 2.00 x 1.44 in. and has .63 in. dia sensing aperture. Absolute accuracy is better than 1%, linearity is better than 0.1%, and phase shift is 1.5° ±1° between measured voltage and current.

Original Press Release:

LEM Introduces High-Performance Split-Core Current Transformers for Energy-efficiency and Active Power Monitoring

Key points:

· For cost-effective power measurement solutions

· Measurement of AC primary currents from 0 to 100A

· High accuracy, excellent linearity and very low phase shift

GENEVA, Switzerland and MILWAUKEE, WI (December 14, 2006) - LEM S.A., the world's leading manufacturer of isolated current and voltage measurement components, announces the TT series of compact split-core AC current transformers. These new devices feature an innovative core material, which enables the TT series to be the first to offer high performance at an attractive price.

The core material used in the transformers is a new type of ferrite with improved magnetic permeability, allowing the accurate measurement of AC signals within an extended frequency range that includes 50/60Hz. The new transformers feature an absolute accuracy better than 1% at the nominal current and even better for lower primary currents. The ferrite material provides an excellent linearity of better than 0.1%, even at very low levels, and the transformers have a particularly low phase shift of 1.5° ±1° between measured voltage and current. The hard and dense core allows very small air gaps and is insensitive to aging and temperature changes, in contrast to laminated FeSi or FeNi materials.

Two ranges of primary current measurement are available: 50A and 100A. The TT 50-SD measures only 1.43 x 1.69 x 1.24 inches (36.5 x 43 x 31.5 mm) with a .31 inch (8 mm) diameter sensing aperture for non-contact measurement. The TT 100-SD measures 1.75 x 2.00 x 1.44 inches (44.5 x 51 x 36.5 mm) with a .63 inch (16 mm) diameter sensing aperture.

With a 3000:1 ratio, the TT 50-SD and TT 100-SD have low output currents (respectively below 16.66 mA or 33.33 mA). This, together with the internal output-protection circuit, guarantees safe and easy installation without the need to shut down operation, since there is no risk of producing a high voltage surge when the transformers are opened, unlike 1A or 5A output products.

Being small, safe, self-powered and split-core, the TT current transformers are easy to install and put into operation. They are ideal for distributed measurement systems and can be retro-fitted into existing installations and non-interruptible equipment. Principal applications will be in the field of energy sub-metering and cost allocation, dynamic consumption and peak analysis, energy waste or defective equipment detection and power quality control.

As with all other LEM industrial products, the TT transformers benefit from high-quality standards and are backed by a five-year warranty.

LEM is a market leader in providing innovative and high quality solutions for measuring electrical parameters. Its core products - current and voltage transducers - are used in a broad range of applications in industrial, traction, energy, automation and automotive markets. LEM's strategy is to exploit the intrinsic strengths of its core business, and develop opportunities in new markets with new applications. LEM is a mid-size, global company with approximately 700 employees worldwide. It has production plants in Geneva (Switzerland), Machida (Japan), Beijing, (China), regional sales offices, and offers a seamless service worldwide. For more further information visit www.lem.com.

For further information please contact:
Ted Smith
Tel: +1-414-434-4303
E-Mail: tms@lem.com
Website: www.lem.com


Perrin McCormick
Hart-Boillot, LLC
Tel: +1-781-893-0053, ext. 15
E-Mail: pmccormick@hartboillot.com

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