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UL Listed R-Coil
/ High Frequency R-Coil


Taehwatrans Flexible Rogowski coils, TFR series, provide best-in-class accuracy for metering and monitoring purpose. They are designed in a way that that their output is hardly influenced by the position of the conductor within the loop and that cross talk, interference from external magnetic fields caused by from nearby conductors, is very low. They show accuracy class 0.5 compliant to IEC61869-10 and less than ±0.5%(max 1%) positioning error around 360 degree of coil loop. They are also UL listed with XOBA/7 UL 2808 & CSA61010-02. They are IP67 protection rating and UV protective so that they show excellent performance in outdoor applications.

They have wide dynamic range where the same coil can be used to measure currents from mA to hundreds of kA. Also they have excellent linearity less than 0.5%. By sophisticated engineering of coil winding and design process, the frequency bandwidth for -3dB ranges from hundreds of kHz and to Mhz. The coreless structure enables Rogowski coils to be used in limited space. Compared with the traditional current transformers, they do not require the power consumption along with an extremely light weight. In the safety aspect, the safe secondary circuit block is not necessary to prevent the damage from the high instantaneous surge current due to an air core usage. In regards to applications, they have the AC accurate measurement, what is more, including the measurement of AC components, ripple current, and DC components.

They are available in different sizes and can be engineered according to customers’ requests, therefore they can be used in all those applications where traditional transducers are not fitting due to its size and/ or weight. TFR series are designed to have strong tolerance against the influence of external magnetic fields, therefore it is capable of an excellent measurement from low currents to hundreds of kA. The Rogowski coils must be connected to an electronic integrator for 90° phase shift compensation and frequency equalization. Integrators sold separately.

Flexible Rogowski coils Features Image


- Revenue-Grade distribution transformer monitoring
- Energy sub-meters
- Pole-top transformer monitoring
- Power quality monitoring
- Condition monitoring
- Distributed measurement systems


- Accuracy class 0.5 by IEC61869-10
- XOBA7 UL 2808 & CSA 61010-02 (Insulation CATⅢ 1000V, Ⅳ 600V)
- Protection Degree IP67 & UV Protective
- Very low positioning errors & excellent orthogonality
- Easy & quick installation in uninterruptible power line
- Adaptable for a large range of coil diameter

I. Flexible Rogowski Coils

> UL2808 & CSA61010-02 600V CATⅣ Pol.Degree Ⅲ


Flexible drawing

Part Number & Dimension


Loop Length 210 320 420 500 620
8.3" 12.6" 16.5" 19.7" 24.4"
53 80 105 130 160
2.1" 3.2" 4.1" 5.1" 6.3"
73 100 125 150 180
2.9" 3.9" 4.9" 5.9" 7.1"

1. Metering Flexible Rogowski Coils

> UL2808 & CSA61010-02 600V CATⅣ Pol. Degree Ⅲ

Electrical Property

Electrical Property

Electrical Properties
Accuracy Class (IEC61869-10) Class 0.5 Operating Frequency 20Hz~20KHz
Output Voltage @1000A,60Hz 120mV Nominal Measurement Current 5A to 6000A
Output Voltage @1000A,50Hz 100mV IP Rating & UV Resistance IP67 & UV Resistive
Phase Displacement < 0.5° Hi-Potential Voltaqe per min. a.c. 7400V
Reading Error (20% Rating) ≤ 0.75% Full Scale Error (Whole Range) ≤ 0.5%
Max Position Error (0° ~ 360°) Avr.± 0.5%(max 1%) Temperature Drift ±0.15% per 10°C
(-40°C ~ +70°C)
Max External Stray Mutual
Inductance Error
(1000A, AC0.5mT)
< 0.1%
Ambient Operating Temp. ­-40°C ~ +70°C Storage Temperature -40°C ~ +80°C

Positioning Error Diagram

2. High Frequency Monitoring Rogowski Coils

Electrical Properties : Model : TFR210LUH

Electrical Property

Electrical Properties
Application Arc Detection Operating Frequency 60KHz - 400KHz
Output Voltage @1A, 400KHz 50mV Hi-Potential Voltage per min a.c.7400V
Max positioning error (0°~360°) Avg.±2% Connected Cable AWG24 600V
Phase Displacement Error < 0.5 IP Rating & UV Resistance IP67 & UV Resistive
Ambient Operating Temp. -40°C ~ +70°C Storage Temperature -40°C ~ +80°C

Frequency Vs Typical Output Gain Diagram

TFR210LUH Frequency Response

· Orthogonal Error

· Positioning Error