Table of Contents
Product Overview: Current Transformer Introduction & Key Value Proposition
A current transformer (CT) is a vital instrument transformer used to measure alternating current (AC) by producing a reduced current proportional to the current flowing in the primary circuit. It enables safe and accurate monitoring and control of electrical systems across industrial, commercial, and utility sectors.
Key value propositions include:
- Accurate current measurement: Converts high primary currents to manageable secondary currents for metering and protection devices.
- Enhanced safety: Isolates secondary circuits from high voltage, protecting equipment and personnel.
- Versatility: Available in various designs such as toroidal CTs, window type CTs, and split core CTs to suit diverse installation needs.
- Compliance and reliability: Engineered to meet strict industry standards and provide consistent performance under different load conditions.
- Wide application range: Supports metering class CTs and protection class CTs with multiple CT ratio options such as 100/5A or 500/1A, enhancing compatibility with existing systems.
With robust design and precise specifications—like burden VA rating, accuracy classes (e.g., 5P10, 5P20), and system voltage adaptability—these current transformers deliver dependable performance for critical electrical infrastructure worldwide.
Key Features & Design Standards
Our current transformers (CTs) are built to meet strict design standards focusing on accuracy, durability, and safety. They come compliant with international regulations such as IEC 60044 (instrument transformer standards), ensuring reliable performance in metering and protection applications.
Compliance & Safety
- Certified Accuracy Classes: Available in metering class CTs (e.g., Class 0.2, 0.5) and protection class CTs (e.g., 5P10, 10P20).
- Safety Standards: Designed with insulation and thermal endurance to protect equipment and personnel.
- Instrument Security Factor (ISF): High ISF values boost system reliability by avoiding false tripping in protection CTs.
Versatility & Mounting Options
Our CTs support various installations for low and medium voltage (LV & MV) systems:
- Toroidal Current Transformers: Compact, highly accurate window-type design for easy cable pass-through.
- Split Core CTs: Quick installation without cable disconnection, ideal for retrofit projects.
- Through-Bore CTs: Suited for large-diameter conductors and busbars.
Mounting Types
- Panel mount
- Busbar clamp
- Floor mount
Each type is designed to suit specific site requirements, maximizing ease of installation and maintenance.
| Feature | Description |
|---|---|
| Compliance | IEC 60044, ANSI standards |
| Accuracy Classes | Metering (0.2, 0.5), Protection (5P10, 10P20) |
| Safety | High insulation, thermal reliability |
| CT Types | Toroidal, Split Core, Window Type |
| Mounting Options | Panel, Busbar clamp, Floor mount |
For detailed insight into transformer core technology impacting CT design, see our guide on dry type transformer core technology.
Technical Specifications: Current Ratio, Burden, Voltage & Frequency
Current transformers come with a range of CT ratio options to fit different measurement and protection needs. Common ratios include:
| CT Ratio | Description |
|---|---|
| 100/5 A | Typical for low to medium currents |
| 500/1 A | Used in high current applications |
Choosing the right CT ratio ensures accuracy and efficiency in current measurement or relay operation.
System Voltage
Current transformers are designed to operate safely and reliably at specified system voltages. Typical voltage classes cover:
- Low voltage CTs: up to 1 kV
- Medium voltage (MV) CTs: 1 kV to 36 kV or higher
Each type meets relevant industry standards to ensure operational safety, with insulation and construction tailored for these voltages.
Frequency Range
Current transformers generally operate within the power system frequency range:
- Standard frequency: 50 Hz or 60 Hz
- Some models support extended ranges for specialized applications
This ensures compatibility with most global electrical grids and their protection systems.
For detailed specifications and technical parameters, you may also want to explore adjacent products like our reliable indoor high voltage vacuum circuit breaker models which complement CT installations in medium voltage setups.
Classification: Metering vs. Protection CTs
Current transformers (CTs) primarily fall into two categories: Metering CTs and Protection CTs, each designed for specific roles in electrical systems.
Metering CTs Function
Metering class CTs are used to measure current for billing, monitoring, and energy management. They provide accurate current signals to meters and instruments. Accuracy is critical here because billing depends on precise data. These CTs typically operate with lower burden VA ratings and are designed for continuous use.
Metering CTs Accuracy Classes
Metering CTs come with strict accuracy classes such as Class 0.2, 0.5, or 1.0, which define the permissible measurement error under specific conditions. These classes ensure that the CT ratio and instrument transformer output maintain accuracy over various loads.
Protection CTs Function
Protection CTs serve a different purpose—they support protective relays and circuit breakers by detecting high fault currents. Their main job is to deliver reliable data even under extreme conditions, like short circuits, to enable swift disconnection and system protection.
Protection CTs Accuracy Classes
While protection CTs don’t require the extreme precision of metering CTs, they need to maintain accuracy during fault conditions. Typical protection CT accuracy classes include 5P10 and 5P20, indicating their ability to accurately replicate current up to 10 or 20 times the rated current without saturation. They also feature a higher burden VA rating for stability during faults.
Understanding the difference between metering class CTs and protection class CTs, along with their respective accuracy and burden VA ratings, is essential for selecting the right current transformer for your system’s needs. For projects requiring coordination with switching equipment, consider pairing CTs with reliable circuit breakers such as those from Kampa Electric’s range of outdoor high voltage vacuum circuit breakers to ensure seamless protection and metering integration.
Selection Guide & Dimensions
Choosing the right current transformer (CT) involves considering the CT ratio, burden (VA rating), accuracy class, and mounting type to match your specific application. Whether you need a toroidal current transformer for compact spaces, a split core CT for easy installation without disconnecting lines, or a window type CT for through-bore applications, size and shape vary to suit every setup.
Key points for selection:
- CT ratio: Select based on your primary current and the secondary current rating needed (common ratios include 100/5A or 500/1A).
- Accuracy class: Metering CTs often require class 0.1 or 0.2, while protection CTs usually need classes like 5P10 or 10P20 for precise fault detection.
- Burden VA rating: Ensure the CT supports the load from connected devices without losing accuracy.
- Mounting style: Options include panel mount, busbar mount, or DIN-rail mount depending on your installation environment.
How to Order
To order, specify all essential parameters:
- CT ratio (e.g., 100/5A)
- Accuracy class (e.g., 5P10 for protection CT)
- Burden rating (VA)
- Physical dimensions and mounting preferences
- Core type (toroidal, split core, window type)
Providing detailed requirements helps ensure you get a CT tailored exactly for your needs.
Dimensional Drawings
We provide precise dimensional drawings for all current transformer models, showing overall size, window dimensions, mounting holes, and terminal positions. These drawings assist in verifying space and compatibility with existing equipment prior to installation.
For a detailed view of current transformers designed for indoor use, check out our cast resin current transformer options which include full dimensional specs and mounting details tailored for MV and LV applications.
Application Areas
Current transformers (CTs) are essential in many sectors for accurate current measurement and protection. Their versatility makes them perfect for a range of industrial, commercial, and utility applications.
- Power Distribution Systems: CTs are widely used in medium voltage (MV CT) and low voltage current transformer setups to monitor and protect electrical networks.
- Substations and Switchgear: Protection class CTs and metering class CTs ensure secure and precise current measurement, helping maintain system stability.
- Industrial Plants: From manufacturing to processing, toroidal current transformers and split core CTs allow easy installation and reliable performance.
- Energy Metering: Metering CTs with high accuracy classes provide precise readings for billing and monitoring energy consumption.
- Renewable Energy: CTs help in managing current flow from solar panels and wind turbines, safeguarding the system.
- Building Management: Through-bore CTs integrate smoothly into existing infrastructure for monitoring and controlling electrical loads.
Kampa Electric supplies high-quality current transformers compliant with global design standards, ensuring safety and reliability in a variety of environments. Their compact designs and variety of CT ratio options make them suitable for any setup. For related equipment, check out our range of dry-type transformers for industrial applications to complement your installation.
Downloads & Resources
Access all essential downloads and resources to support your use of our current transformers. Here, you’ll find detailed datasheets, user manuals, and installation guides covering key specs like CT ratio, burden VA ratings, accuracy classes, and mounting instructions. These resources help you select and apply the right metering class CT or protection class CT for your electrical system with ease.
Whether you’re working with toroidal current transformers, split core CTs, or through-bore CTs, our comprehensive documentation ensures that you have the technical details you need at your fingertips. Need specific standards or compliance info? We include charts outlining accuracy limit factors and instrument security factors critical for precise current measurement and protection.
For high-voltage applications, check out related technical materials for indoor cast resin current transformers and outdoor current transformers, giving you insights into their design and performance under various system voltages and frequencies. These resources are tailored to guide you through everything from product selection to installation to maintenance.
Explore our LZZBJ9 indoor cast resin current transformer ocumentation and LZZBW-35 outdoor current transformers specs for additional technical details relevant to your project needs.
All downloads and manuals are available in clear, easy-to-understand English, helping you make informed decisions and optimize your electrical installations effectively.
Request a Quote / Contact Kampa
Looking for a reliable current transformer that fits your specific needs? At Kampa, we offer a wide range of metering and protection class CTs with various CT ratio options and accuracy classes. Whether you need a toroidal current transformer, window type CT, or a split core CT for low or medium voltage applications, our experts are ready to assist.
Get in touch with Kampa today to request a quote or discuss the perfect instrument transformer solution including details on burden VA rating, rated system voltage, and accuracy limits tailored to your project. Simply fill out our contact form below or reach out directly. Our team is committed to providing fast, clear answers to ensure you get exactly what you need.
Explore high-quality current transformers with Kampa – your partner in precision and safety.