Current Sensor (Current Transformer)

Product Specifications

Technical details and manufacturing context for Current Sensor (Current Transformer)

Definition

This current sensor, based on current transformer technology, is a component used in electrical equipment manufacturing. It is designed to measure alternating current (AC) in power systems by transforming high primary currents into proportional, lower-level secondary currents. The sensor is typically installed within grid monitoring devices, where it provides accurate current data for load monitoring, fault detection, protection schemes, and system stability management. It operates on the principle of electromagnetic induction: the primary conductor passes through a magnetic core, inducing a secondary current in the winding. This stepped-down current is then converted to a standardized output signal (voltage or digital) for measurement and monitoring equipment. The sensor is available with a range of technical parameters that must be selected based on the specific application. Key parameters include rated primary current (5–5000 A), rated secondary current (1 or 5 A), accuracy class (0.5–5P20), rated burden (2.5–30 VA), rated frequency (50–60 Hz), rated insulation level (0.72–72.5 kV), rated short-time thermal current (10–50 kA), rated dynamic current (25–125 kA), operating temperature (-40 to 85 °C), degree of protection (IP54–IP65), insulation class (E–H), and weight (1–50 kg). These values are reference ranges and must be verified for the actual model and application. The sensor complies with relevant IEC standards, including IEC 61869-1, IEC 61869-2, IEC 60529, and IEC 60085, which serve as procurement and verification references. Materials used include silicon steel core, copper windings, epoxy resin insulation, and polymer housing. For proper selection, consider the maximum load current, required accuracy, connected burden, system voltage, and installation environment. Always verify model-specific values and standards with the legal manufacturer or supplier before procurement.

Working Principle

The sensor operates on the principle of electromagnetic induction. The primary conductor carrying the current to be measured passes through the magnetic core, inducing a proportional secondary current in the winding. This stepped-down current is then converted to a standardized output signal (typically voltage or digital) for measurement and monitoring equipment. The transformation ratio is determined by the number of turns in the secondary winding. The core material, typically silicon steel, ensures efficient magnetic coupling. The secondary current is typically 1 A or 5 A, which is suitable for standard protection and metering devices. The sensor must be selected based on the rated primary current, accuracy class, and burden to ensure accurate measurement and safe operation.

Common Materials

Silicon steel core, Copper windings, Epoxy resin insulation, Polymer housing

Technical Parameters

Parameter	Typical range	Notes & selection driver
Rated Primary Current	5–5000 A	Select based on max load currentIEC 61869-1
Rated Secondary Current	1 or 5 A	Standard output for protection and meteringIEC 61869-2
Accuracy Class	0.5–5P20	Metering: 0.2–0.5; Protection: 5P/10PIEC 61869-2
Rated Burden	2.5–30 VA	Must match connected loadIEC 61869-2
Rated Frequency	50–60 Hz	Other frequencies on requestIEC 61869-1
Rated Insulation Level	0.72–72.5 kV	System voltage classIEC 61869-1
Rated Short-Time Thermal Current	10–50 kA	Withstands fault current for 1sIEC 61869-2
Rated Dynamic Current	25–125 kA	Peak withstand without damageIEC 61869-2
Operating Temperature	-40–85 °C	Extended range availableIEC 61869-1
Degree of Protection	IP54–IP65	Indoor/outdoor installationIEC 60529
Insulation Class	E–H	Thermal endurance of insulationIEC 60085
Weight	1–50 kg	Depends on rated voltage and current

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Magnetic Core Part
Provides the magnetic path for electromagnetic induction and determines the transformation characteristics

Material: Silicon steel laminations
Primary Conductor Part
Carries the current to be measured through the transformer window

Material: Copper or aluminum busbar
Secondary Winding Part
Produces the proportional output current through electromagnetic induction

Material: Copper wire with insulation
Insulation System
Provides electrical isolation between primary and secondary circuits and protects against environmental factors

Material: Epoxy resin, polymer compounds
Terminal Block
Provides secure electrical connections for input and output signals

Material: Copper alloy with insulating base

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Current Sensor (Current Transformer).

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Grid Monitoring Device

View system integration details

Manufacturers of Current Sensor (Current Transformer)

Manufacturer profiles associated with Current Sensor (Current Transformer).

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review · Page last updated 16 September 2026

Procurement Evaluation Criteria

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Frequently Asked Questions

What is the operating principle of this current sensor?

It operates on electromagnetic induction. The primary conductor passes through a magnetic core, inducing a proportional secondary current in the winding. This current is then converted to a standardized output signal for monitoring and protection.

What are the key selection parameters?

Key parameters include rated primary current (5-5000 A), rated secondary current (1 or 5 A), accuracy class (0.5-5P20), rated burden (2.5-30 VA), rated frequency (50-60 Hz), insulation level (0.72-72.5 kV), and short-time thermal current (10-50 kA). These must be matched to the application.

What standards apply to this sensor?

Relevant standards include IEC 61869-1 (general requirements), IEC 61869-2 (current transformers), IEC 60529 (degree of protection), and IEC 60085 (insulation class). These are verification references; compliance must be confirmed with the manufacturer.

How should I verify the sensor's suitability for my system?

Check the rated primary current against your maximum load, ensure the accuracy class meets metering or protection needs, verify the burden matches connected devices, and confirm insulation level and protection rating for your installation environment. Always consult the manufacturer for model-specific data.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	Atmospheric to 1.2 bar (typical for non-sealed units)
other spec:	Frequency range: 50/60 Hz to 400 Hz, Accuracy: ±0.5% to ±3% FS, Insulation voltage: 0.5 kV to 10 kV RMS
temperature:	-40°C to +85°C (operating), -55°C to +105°C (storage)

Product Specifications

Industry Taxonomies & Aliases

Applied To / Applications

Industrial Ecosystem & Supply Chain Structure

Application Fit & Sizing Matrix

Reliability & Engineering Risk Analysis

Compliance & Manufacturing Standards