At SPS 2019, LEM announced the development of the Rogowski coils range to measure current up to 300,000 A AC with accuracy class 0.5. The ARU range reaches IEC 61869-10 class 0.5 without the need for additional components (resistors or potentiometers to calibrate the coil, which can drift over time). The range takes advantage of the ‘Perfect Loop’ technology, which is a unique patented coil clasp that eliminates the inaccuracy caused by sensitivity to the position of the conductor inside the loop. This technology provides an innovative, robust and fast ‘Twist and Click’ closure.
The ARU range can be installed outdoors as it complies with UV, water, dust and ice resistance standards. The material used is ruggedized to be durable in harsh environments, with an operating temperature range from -40 to +80°C. The range is offered with an internal shield to protect against external fields, improving accuracy and optimizing performance for small current measurements. It can be quickly mounted by clipping on the cable to be measured. Contact with the cable is not necessary, while the ARU models enable a high level of safety and a high rated insulation voltage (1000 V Cat III PD2 – reinforced).