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Clamp-on Current Transformer


Clamp-on Current Transformer

Clamp-on Current Transformer, TSR and TPR series, provide excellent accuracy mainly for 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 1.0 compliant to IEC61869-10 and less than ±1.0% positioning error around 360 degree of coil loop. TSR series are also UL recognized. They are IP65 protection rating and UV protective so that they show reliable performance in outdoor applications.

Clamp-on Current Transformer 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 1.0%. 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.

Clamp-on Current Transformer 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. TSR and TPR 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.

Clamp-on Current Transformer

Clamp-on Current Transformer Application

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

Clamp-on Current Transformer Features

- Accuracy class 1.0 by IEC61869-10
- UL Recognized
- Protection Degree IP65 & UV Protective
- Very low positioning errors & excellent orthogonality
- Easy & quick installation in uninterruptible power line
- VAdaptable for a large range of coil diameter

Clamp-on CT TSR Drawing

TSR Series


TSR Electrical Property & Dimension



Specification Spec
Model No A(min) B(max) C(max) D(max)
TSR35L/C 35.0(1.378") 83.0(3.268") 20.9(0.823") 99.5(3.917")
TSR115L/C 114.5(4.508") 151.2(5.953") 22.4(0.882") 173.0(6.811")
TSR145L/C 145.0(5.709") 190.0(7.480") 22.5(0.886") 210.0(8.268")

* L : 600V cable
* C : BNC Connector

Electrical Property

Electrical Property
Accuracy Class
"Class 1.0
(Reading Accuracy)"
Max Short
Circuit Current
40kA @RL 1MΩ
Nominal Measurement Current 5A - 6000A Operating Voltage a.c. 600V
Output Voltage @1000A "90mV ± 5%(60Hz)
75mV ± 5%(50Hz)"
Hi-Potential Voltage(per min.) a.c. 25kV
Phase Displacement 0.05° (Degree) IP Rating & UV Resistance IP65 & UV Resistive
Positioning Error (0° ~ 360°) Avr.± 1.0% (max. 1.5%) Ambient Operating Temp. 40°C ~ +70°C
Mutual Inductance 239nH / 60Hz Storage Temperature -40°C ~ +80°C
Max External Stray
Mutual Inductance Error @0.5mT
"≤0.15%(1000A)≤1.5%(100A)" Cable 24AWG, 600V

Clamp-on CT TPR26 Drawing

Electrical Properties-Drawing

TPR26 Electrical Property & Dimension



Specification Spec
A(min) B(max) C(max) D(max) F(±5) F'(±3) G(±1)
26 80.3 28 80.6 600 40 10
1.024" 3.161" 1.102" 3.173" 23.622" 1.575" 0.394"

Electrical Property

Electrical Property
Accuracy Class
Class 1.0
(Reading Accuracy)"
Hi-Potential Voltage a.c. 15kV/ 1min.
Nominal Measurement Current 5A - 6000A Max Current @1MΩ 400,000A
Output Voltage @1000A 90mV ± 6%(60Hz) Max External Stray
Mutual Inductance Error @0.5mT
Phase Displacement 0.05° (Degree) Ambient Operating Temp 40°C ~ +70°C
Mutual Inductance @ 60Hz 239nH Storage Temperature 40°C ~ +80°C

Clamp-on Rogowski Coils