TECHNICAL SUPPORT

OUTDOOR CURRENT TRANSFORMER FOR REVENUE-GRADE DISTRIBUTION TRANSFORMER MONITORING

● OUTDOOR OPEN-TYPE ROGOWSKI COIL

In generally, Outdoor Split-core CT which is being used for distribution transformer monitoring, is designed to fulfill IP67 standard. However, these current sensors are vulnerable to the external circumstances such as UV, rain, wind, vibration and lightning surge. Therefore, current sensors have to be covered with a protective housing when it is installed, to protect from external influence which results in increasing of the installation and maintenance costs. In addition, Split-core CT inheres the problems of phase shift or ratio error, which are caused from the varying air gap when occur the cores combined. To solve these problems, J&D has launched precise current sensors for Revenue-Grade Distribution Monitoring, named iSAST OUTDOOR OPEN-TYPE RCT-M.

iSAST OUTDOOR OPEN-TYPE RCT-M series is based on Rogowski Coil technology. Utilizing a high-precision coil winding technique offers minimal accuracy variance over the wide operating current range, and reduces positional errors caused by the varying position of current sensor on the primary conductor. Advanced shielding techniques minimize the influences of external magnetic fields. The split, open flexible structure enables the product to be easily installed on the power line, even in the narrow spaces and live. As iSAST OUTDOOR OPEN-TYPE RCT-M series is composed of an Air Core, it is less affected to the external circumstances such as UV, rain, wind, vibration and lightning surge. In addition, RCT-M series fulfills the standard IP67, UL2808 and IEC60044-8 with 0.5S class of accuracy, and also, it has acquired the international safety certification; IEC61010-1, IEC61010-2-032, UL61010-1, UL61010-2-032 and EN61010-1, EN61010-2-032. iSAST OUTDOOR OPEN-TYPE RCT-M series is designed with the two different configurations; one is Rogowski Coil with built-in voltage integrator, and the other is Rogowski Coil without integrator. In the case of Rogowski Coil without voltage integrator, the smart meter manufacturer or transformer monitoring company can configure the voltage integration function by themselves. On the other hand, Rogowski Coil with voltage integrator can replace the existing CT directly. In case of designing their product with the voltage integration, developer takes into consideration the 90-degree phase difference, before applying the signal to the smart meter or transformer monitoring equipment. iSAST OUTDOOR OPEN-TYPE RCT-M series can measure 100A to 6,000A of rated primary current, and satisfy the inner diameter of 35, 55, 80, 105, 115, 125mm. There are the two configurations; RCT-M series with voltage integrator, and RCT-M series without integrator.

● THE NEW PROGRESS OF OUTDOOR SPLIT-CORE CURRENT TRANSFORMER

Global leading power utility service companies recognize the problems of conventional split core outdoor CTs, which are vulnerable to external environmental factors such as UV, rain, wind and lightning surge. In addition, engineers who design power & energy monitoring systems are aware that split core outdoor Rogowski coil CTs are very sensitive to external field and also know its danger to install CTs when the primary current is “live.” To resolve these problems, J&D has developed new innovative split core outdoor Rogowski coil CTs. First, JRF MOI series enable high-performance and easy installation based on precise winding on the air-core combined integrator and superb shielding technology. Second, the JOS series is designed with advanced waterproofing and a perfect housing technology for strong durability. In addition, J&D’s new JRF MOI & JOS split core outdoor CTs are cost-effectiveness, making them part of the perfect solution.

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