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Model RCTrms flexible "rope type" current transformer

For fast clip-around installation with true rms output

The RCTrms is an AC Rope CT (current transducer) for permanent installation. Simple to install and easy to retrofit, it combines the benefit of a thin, flexible, clip-around Rogowski (sense) coil with a signal conditioner providing accurate, true rms measurement of ac current.

The RCTrms has an industry standard 0-5V or 4-20mA dc output making it ideal for process control, status alarming or system monitoring purposes. Typically the RCTrms is used with SCADA systems, PLCs, data loggers and protection equipment. The RCTrms gives a dc output proportional to the true rms of the primary current and has these advantages:

  • Easy to retrofit
  • Simple to install in applications where space is limited
  • The size of the Rogowski coil can be specified independently of the primary current
  • Does not suffer from magnetic saturation
  • Intrinsically safe
  • Ideal for process control, status alarming or system monitoring in a wide variety of applications, from arc furnaces to power distribution

The available RCTrms current ranges are 0-100A to 0-50,000Apk, also providing accurate measurement over a wide bandwidth ensuring precise measurement even with harmonically distorted waveshapes - using a flexible clip-on sensing coil.

The RCTrms sensor can provide all popular process control voltage and current loop outputs along with custom output options. Because the current sensors are split core, installation is possible without shutting down the electrical supply - saving down-time costs. Typical applications are retrospective energy monitoring in factories, offices, process control systems like PLC, SCADA Data logging systems, all where power, energy and current monitoring is important. Typical loading situations are factories, shops, offices, ac/dc VFD drives, ultrasonics, welding, power conversion and power distribution. For all RCTrms models, a NIST/NPL (UKAS) traceable calibration certificate and certificate of conformance is supplied. All RCTrms sensors use UL or CSA approved materials.

For level sensing, alarm and threshold monitoring please see Trip relay

RCTrms series flexible split core current sensors with 0-5V or 4-20mA outputs, avoiding LV & HV shutdown
RCTrms single phase
RCTrms Three phase available soon
Includes signal conditioner and power

Further information:

Basic Operation | Accuracy | Response Time | Ratings
RCT Models and ranges
  • RCTrms - Range 100A
  • RCTrms - Range 250A
  • RCTrms - Range 500
  • RCTrms - Range 750A
  • RCTrms - Range 1000A
  • RCTrms - Range 1500A
  • RCTrms - Range 2000A
  • RCTrms - Range 2500A
  • RCTrms - Range 4000A
  • RCTrms - 5000A
  • RCTrms - 8000A
  • RCTrms - 10000A
  • RCTrms - 15000A
  • RCTrms - 20000A
  • RCTrms - 25000A
  • RCTrms - 40000A
  • RCTrms - 50000A
RCT Models and ranges
  • Available sense coil lengths 300, 500 or 700mm
  • Optional mini coils, 3.5mm thickness, 100, 200 or 300mm length
  • Isolated measurement output
  • 0-5V or 4-20mA outputs
  • 2kV insulation continuous (tested 4kV) / 10kV optional (tested 15kV)
  • < 1% accuracy from 5%-150% of range
  • Bandwidth 0.6Hz to 100kHz
  • Operation to 150% FS 10.6Vpk
  • 12, 24, 48, 125Vdc or 110Vac, 220Vac power supply options, see *
  • Operating range -5°C to +65°C
  • Safety EN61010:2001
  • CE marked
RCTrms Current sensor order codes

RCTrms / range / output / power supply / coil length mm

1000A range, 0-5V output with 24Vdc power and 500mm coil length = RCTrms / 1000 / 005 / D24 / 500


Optional 3.5mm diameter 100, 200 or 300mm sense coils

* to meet CE / UL safety requirements, an external power adapter is supplied for 125Vdc, 110Vac and 230Vac options

All products have CE, IEC, EN, ASME or BS approvals.

Further information:

Basic Operation | Accuracy | Response Time | Ratings