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China Current Transformer (CT) Suppliers - High-Quality Factory Solutions for Power System Monitoring and Protection
Product Overview
A CT is powered by electromagnetic induction and contains two windings: a main winding with a few turns connected in series to the high-current circuit and a secondary winding with several turns connected to safety or measurement devices. The primary winding receives a large current, but the secondary winding, which is typically tuned to 5A or 1A for most industrial applications, receives a little current. This proportionality, also known as the transformation ratio, enables for precise current measurement while protecting personnel and equipment from potentially harmful voltages.
CTs require enough insulation to maintain a high voltage between windings, linearity to reduce measuring error, and high precision for energy metering. When utilizing a CT, never leave the secondary winding open circuit. This is because an open circuit may generate extremely high voltages, which can damage electrical equipment. Finally, since they allow for more precise current monitoring and enhanced issue avoidance, current transformers are critical to assuring the dependability, efficiency, and safety of contemporary electrical systems.
CTs require enough insulation to maintain a high voltage between windings, linearity to reduce measuring error, and high precision for energy metering. When utilizing a CT, never leave the secondary winding open circuit. This is because an open circuit may generate extremely high voltages, which can damage electrical equipment. Finally, since they allow for more precise current monitoring and enhanced issue avoidance, current transformers are critical to assuring the dependability, efficiency, and safety of contemporary electrical systems.
Important Notice: Never leave the secondary winding open circuit. An open circuit may generate extremely high voltages, which can damage electrical equipment and pose serious safety risks.
High Insulation
Maintains high voltage separation between windings for safe operation.
Precise Linearity
Reduces measuring error for accurate energy metering applications.
Standard Output
Secondary winding tuned to 5A or 1A for most industrial applications.
Technical Parameters
| Type | Specification | (mm) Outline Size | ||||||
|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E | F | M | ||
| CTFK-1025 | 100A/5A | 162 | 71 | 28 | 155 | 100 | 25 | c5*7 |
| CTFK-1435 | 250A/5A | 202 | 81 | 28 | 195 | 140 | 35 | c5*7 |
| CTFK-1835 | 400A/5A | 242 | 82 | 28 | 235 | 180 | 35 | c5*7 |
| CTFK-2245 | 630A/5A | 282 | 92 | 28 | 275 | 220 | 45 | c5*7 |
| CTFK-3045 | 1250A/5A | 363 | 92 | 28 | 355 | 300 | 45 | c5*7 |
| Accuracy Grade: 1.0 | Overload Current: ≥1.2% ln | |||||||
Frequently Asked Questions
Q
What is a Current Transformer (CT) and how does it work?
A Current Transformer (CT) operates on the principle of electromagnetic induction. It consists of a primary winding connected in series with the high-current circuit and a secondary winding connected to measurement or safety devices. The large current in the primary winding induces a proportionally smaller current in the secondary winding, enabling safe and accurate current measurement.
Q
What are the standard secondary output ratings for industrial CTs?
For most industrial applications, the secondary winding of a CT is typically tuned to either 5A or 1A. The CTFK series models listed in the technical parameters all feature a standard 5A secondary output, with primary ratings ranging from 100A to 1250A depending on the model selected.
Q
Why should the secondary winding of a CT never be left open circuit?
Leaving the secondary winding open circuit is extremely dangerous. Without a connected load, the CT attempts to maintain its transformation ratio, which can generate extremely high voltages across the open terminals. These high voltages can damage electrical equipment, degrade insulation, and pose a serious safety hazard to personnel. Always ensure a burden is connected before energizing the circuit.
Q
What accuracy grade do the CTFK series current transformers offer?
The CTFK series current transformers are rated at Accuracy Grade 1.0, making them suitable for energy metering and precise measurement applications. They also support an overload current of ≥1.2% In, ensuring reliable performance under varying load conditions.
Q
How do I select the correct CTFK model for my application?
Model selection is based primarily on the primary current rating of your circuit. For example, if your circuit carries up to 400A, the CTFK-1835 (400A/5A) would be appropriate. You should also consider the physical outline dimensions (A through M) to ensure the CT fits within your installation space. Refer to the Technical Parameters table for full dimensional specifications.
Q
What are the key performance requirements for a current transformer?
A high-quality current transformer must meet three critical performance requirements: sufficient insulation to maintain safe voltage separation between primary and secondary windings; strong linearity to minimize measuring errors across the operating range; and high precision to support accurate energy metering. The CTFK series is engineered to meet all these requirements for demanding industrial environments.