{"id":1997,"date":"2026-09-29T10:03:18","date_gmt":"2026-09-29T15:03:18","guid":{"rendered":"https:\/\/blog.hilltech.com\/?p=1997"},"modified":"2026-09-29T10:03:20","modified_gmt":"2026-09-29T15:03:20","slug":"new-current-transformer-the-csr101","status":"publish","type":"post","link":"https:\/\/blog.hilltech.com\/?p=1997","title":{"rendered":"New Current Transformer: the CSR101"},"content":{"rendered":"
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\"CSR101<\/figure><\/div>\n\n\n

Switchgear designers are pushing tech forward with new ideas and more efficient and precise specifications. They need current sensors for their medium voltage switchgears that can keep up by accurately measuring and monitoring currents across a vast operating range without the issues that come with conventional magnetic-core current transformers. That\u2019s where Amran comes in by introducing their new CSR101 Current Sensing Rogowski, or the Rogowski CT, and its air-core design.<\/p>\n\n\n\n

What is it?<\/h2>\n\n\n\n

This new current transformer, the CSR101, is used with protecting insulated bushings and cables, along with conductors within enclosures. It is similarly packaged to Amran\u2019s CT101 format and is designed specifically to bring aid the next generation of current-sensing applications.<\/p>\n\n\n\n

It excels at current measurement for protection, monitoring, and metering in medium voltage air-insulated switchgear. This device combines a high primary current measurement range with a compact installation format and a shielded RJ45-type secondary connection.<\/p>\n\n\n\n

Air-Core Rogowski Technology<\/h2>\n\n\n\n

Conventional current transformers use ferromagnetic cores, but the CSR101 uses an air-core Rogowski coil due to its ability to accommodate a large range of primary current without the core saturation concerns that a normal current transformer has to deal with. This coil\u2019s output voltage is proportional to the derivative of the primary current.<\/p>\n\n\n

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\"CSR101<\/figure><\/div>\n\n\n

Configuration<\/h2>\n\n\n\n

The CSR101 sensor is designed to convert current in the primary circuit into an appropriate signal for secondary equipment, while also maintaining electrical insulation between the primary and secondary circuits.<\/p>\n\n\n\n

Its 165 mm inner diameter provides a large sensing window for installation around the primary conductor.<\/p>\n\n\n\n

For its secondary connection, the sensor uses a CAT61 RJ45 female connection, with Sensor 1 and Sensor 2 connected to pins 1 and 2, respectively. This RJ45-type connection allows the secondary wiring to maintain shielding for applications were electromagnetic compatibility (EMC) are essential.<\/p>\n\n\n\n

The CSR101 is supplied with A female RJ45-type receptacle (commonly known as an Ethernet jack\/socket), avoiding the limitations of a permanently attached secondary cable. This allows you to use a shielded cable that you can create and directly connect to whatever length you require. It\u2019s located on the protection relay side. Typically, the cable length is no more than 5 meters (though shorter lengths are acceptable). The RJ45-style interface, though, allows the secondary connection to use standard CAT6-compatible connections. Long sensor cables should be secured approximately 10 cm from the RJ45 socket with a cable tie to help protect the connector.<\/p>\n\n\n\n

Specifications<\/h2>\n\n\n\n

This sensor is versatile can provide accurate current information during both normal operating conditions and significantly higher current conditions. These are due to its stellar specifications, as listed below:<\/p>\n\n\n\n

Rated primary current: 80 A<\/p>\n\n\n\n

Rated continuous thermal current: 4,000 A<\/p>\n\n\n\n

Extended primary current factor: 50 A<\/p>\n\n\n\n

Rated frequency: 50\/60 Hz<\/p>\n\n\n\n

Stated accuracy classification: 0.5\/5P630<\/p>\n\n\n\n

Rated secondary output: 150 mV at 50 Hz \/ 180 mV at 60 Hz<\/p>\n\n\n\n

Standard: IEC 61869-1 and IEC 61869-10<\/p>\n\n\n\n

UL\/cUL Recognized: UL File E205113<\/p>\n\n\n\n

The current amplitude correction factor and phase error correction factor are determined individually for each sensor during routine testing. These values are provided on the sensor nameplate.<\/p>\n\n\n\n

Uses<\/h2>\n\n\n\n

For switchgear manufacturers, the CSR101 is perfect for:<\/p>\n\n\n\n