I. Product Overview & Engineering Design

Introduction

Solid core current transformers (CTs) are essential instrument transformers designed to provide accurate current measurement and reliable electrical protection. Featuring a robust toroidal core, these through-hole current transformers are widely used in low voltage CT applications to monitor and control electrical systems effectively. The solid core design ensures consistent performance in demanding industrial and utility environments.

Design Philosophy

Our solid core current transformers prioritize precision, durability, and safety. Built with high-permeability magnetic materials and engineered winding configurations, they offer exceptional accuracy classes such as 0.5 for metering and 5P10/10P for protection class CTs. The design emphasizes minimal magnetic losses and stable thermal performance, making them ideal for both metering class current transformer and protection class CT requirements. The window type construction enables easy cable or busbar insertion, ensuring seamless integration.

Installation Scope

These ring type CTs are adaptable to a wide range of installations, from panel mount current transformers in distribution boards to busbar current transformer setups in switchgear. Their solid core architecture supports current ratio options like 100/5A or custom secondary current outputs (1A/5A), matching diverse application needs. Installation is straightforward with various mounting accessories, accommodating space constraints and simplifying electrical system integration.

II. Technical Specifications of Solid Core Current Transformer

Understanding the technical specs of a solid core current transformer (CT) helps you get the right fit for your needs, from accuracy to safety. Here’s a clear covering the essential points:

Current Ratio Ratings

Common primary to secondary current ratios include 100/5A, 200/5A, and customized options. The secondary current output typically comes in 1A or 5A, suitable for most low voltage CT applications and instrumentation needs. This ratio ensures safe, precise current measurement by stepping down high primary currents.

Accuracy & Performance Classes

Accuracy classes dictate how precise the CT readings are. Metering class CTs generally have Class 0.5 or 1.0 accuracy, ideal for billing and energy metering. Protection class CTs come in 5P10, 10P, built to hold up under fault conditions with reliable operation.

Burden & Output (VA Rating)

The burden rating indicates the load the CT can handle without compromising accuracy. Typical burden values range from 5VA to 15VA, depending on the application, ensuring minimal signal distortion for both metering and protection uses.

Insulation & Safety

Solid core CTs feature robust insulation designed for low voltage environments. They meet international safety standards, offering protection against electrical faults and ensuring durability in panel mount or busbar-mounted systems. The insulation class supports safe operation under specified voltage levels, with increased resistance against transient spikes.

For more on transformer variations, you can check our details on split core CT current transformers designed for flexible installation without downtime.

This concise technical helps you quickly pinpoint solid core current transformers that fulfill your performance and safety requirements in industrial or commercial setups.

Selection Guide: How to Specify Your Wilmall Solid Core Current Transformer

Choosing the right solid core current transformer (CT) from Wilmall is simple when you follow these three key steps:

Step 1: Determine the Current Ratio

The current ratio is fundamental. It specifies the relationship between the primary current and the secondary current output, commonly shown as 100/5A, 200/5A, or sometimes with secondary current at 1A or even milliamps (mA). This ratio ensures compatibility with your system and measurement devices.

Choosing the right ratio avoids overloading and guarantees accurate readings. For more details on available ratios and specifications, check Wilmall’s full range of current transformers for energy meters and protections.

Step 2: Choose the Application (Metering vs. Protection)

Wilmall solid core CTs come in metering class and protection class:

• Metering Class CTs (0.2, 0.5, 1.0 Accuracy Classes): Ideal for billing, energy monitoring, and precise measurements.
• Protection Class CTs (5P10, 10P Accuracy Classes): Designed for relay protection, fault detection, and safety systems, built to handle transient conditions and overloads.

Select the class based on your accuracy needs: metering for detailed consumption data or protection for system safety and fault detection.

Step 3: Size the Window (Aperture) Correctly

The window or aperture size of the CT must match the conductor or busbar it encircles. Ill-fitting CT windows result in poor installation or inaccurate measurements.

• Measure the conductor thickness or busbar size.
• Choose a CT with a window large enough to comfortably fit the conductor without forcing it.
• Wilmall offers various toroidal ring type CTs or busbar CTs with different aperture sizes for easy installation.

Quick Selection Table

Following this guide ensures your Wilmall CT fits your system perfectly—whether for precise metering or robust protection.

Explore more on selecting and using different current transformers at Wilmall’s current transformer product page.

Dimensional Drawings & Mounting Options

When working with a solid core current transformer, knowing the exact dimensions and mounting choices is key for a smooth installation. These ring type CTs come with detailed schematics showing the window size, overall dimensions, and terminal layout, ensuring compatibility with your setup.

Key Dimensions (Typical Solid Core CT)

Mounting Options

• Panel Mount: Secure the CT directly onto a control panel using screws and brackets, ideal for compact installations.
• Busbar Mount: Clamp the CT around busbars; the solid core design ensures a snug fit for accurate metering.
• DIN Rail Clip: Some models offer optional clips for quick DIN rail attachment, simplifying maintenance.

Mounting Accessories

• Brackets and screws tailored for ring type CTs
• Insulation pads for electrical safety
• Terminal covers to protect secondary connections

For a smooth installation with assured accuracy, double-check your required aperture size and terminal layout using the full dimensional schematics provided by suppliers. If you’re interested, you might also want to explore our low voltage current transformer models with accuracy class 0.5, which come with comprehensive mounting options.

V. Common Applications of Solid Core Current Transformers

Solid core current transformers (CTs) are widely used in both industrial and commercial electrical systems. Their robust design and reliable performance make them ideal for various applications, particularly where precise current measurement and protection are critical.

Typical Uses Include:

• Metering and Billing: Accurate metering class current transformers with an accuracy class of 0.5 or 1.0 are common in energy monitoring systems. These CTs convert high primary currents (such as 100/5A) to manageable secondary currents for meters and data acquisition units, helping utilities and facility managers track consumption precisely.
• Protection Systems: Protection class CTs (like 5P10 or 10P) are vital in circuit breakers and relay panels. They ensure precise fault detection and system protection by quickly and reliably providing the current signals needed to trip protection devices in case of overload or short circuits.
• Panel and Busbar Monitoring: Solid core ring type or toroidal CTs with window apertures are often mounted on busbars or inside control panels. These busbar current transformers provide continuous current monitoring for switchgear and panel boards, supporting both metering and protective functions.
• Current Sensing in Switchgear: Through-hole current transformers with appropriately sized windows allow easy installation around conductors without disconnecting circuits. They are preferred in retrofit and maintenance projects where downtime must be minimized.
• Industrial Equipment Monitoring: AC current transducers built with solid core CTs help monitor motors, transformers, and other equipment to optimize performance and detect abnormalities.

For specific needs, such as specialized instrument transformers or low voltage CTs, Wilmall offers tailored options. Refer to products like our indoor single-phase epoxy resin voltage transformer for complementary solutions in power measurement and protection setups.

No matter the application, choosing the right solid core current transformer with the appropriate current ratio, secondary current (1A or 5A), and burden rating (VA) will ensure accurate readings and reliable system protection in your electrical network.

VI. Frequently Asked Questions (Technical FAQ)

Here are answers to common questions about solid core current transformers (CTs), covering key points like ratio, accuracy, and installation.

For extra tips on choosing the right CT for your setup, refer to our selection guide and explore related products like split core CTs for easier installation. For more support on industrial instrumentation, check out our article on how to choose a suitable proximity switch.