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China Current Transformer (CT) Suppliers and Factory for Power Monitoring and Protection Solutions
Product Overview
A CT uses electromagnetic induction and consists of two windings: a secondary winding with several turns connected to safety or measurement devices, and a primary winding with a few turns connected in series to a high-current circuit. The secondary winding, which is typically tuned to 5A or 1A for the majority of industrial applications, gets minimal current while the primary winding receives a lot. This proportionality, also known as the transformation ratio, protects people and equipment from dangerous voltages while allowing for precise current monitoring.
CTs need sufficient insulation to sustain a high voltage between windings, linearity to reduce measurement error, and high precision for energy metering. The secondary winding should never be left open circuit while utilizing a CT. This is due to the possibility that an open circuit may produce extraordinarily high voltages that could harm electrical equipment. Lastly, current transformers are essential to guaranteeing the dependability, effectiveness, and safety of contemporary electrical systems since they allow for more accurate current monitoring and enhanced problem diagnoses.
CTs need sufficient insulation to sustain a high voltage between windings, linearity to reduce measurement error, and high precision for energy metering. The secondary winding should never be left open circuit while utilizing a CT. This is due to the possibility that an open circuit may produce extraordinarily high voltages that could harm electrical equipment. Lastly, current transformers are essential to guaranteeing the dependability, effectiveness, and safety of contemporary electrical systems since they allow for more accurate current monitoring and enhanced problem diagnoses.
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Important Safety Notice: The secondary winding should never be left open circuit while utilizing a CT. An open circuit may produce extraordinarily high voltages that could seriously damage electrical equipment and pose safety hazards.
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Electromagnetic Induction
Operates via two windings — primary (high-current) and secondary (5A or 1A output).
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High Insulation
Sufficient insulation sustains high voltage between windings for safe operation.
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High Precision
Excellent linearity reduces measurement error for accurate energy metering.
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Enhanced Diagnostics
Enables more accurate current monitoring and improved fault detection.
Technical Parameters Accuracy Grade: 0.5
| Type | Specification | Lead Length | (mm) Outline Size | |||||
|---|---|---|---|---|---|---|---|---|
| c | A | B | C | D | M | |||
| CTY-45 | 100A / 5A | 1m | 45 | 79 | 84 | 24 | 66 | c5×8 |
| CTY-65 | 250A / 5A | 1m | 65 | 100 | 104 | 24 | 86 | c5×8 |
| CTY-80 | 400A / 5A | 1m | 80 | 114 | 119 | 26 | 101 | c5×8 |
| CTY-100 | 630A / 5A | 1m | 100 | 136 | 141 | 26 | 114 | c5×8 |
| Accuracy Grade: 0.5 | Overload Current: ≥1.2% ln | |||||||
Frequently Asked Questions (FAQ)
Q
What is a Current Transformer (CT) and how does it work?
A Current Transformer (CT) works on the principle of electromagnetic induction. It consists of a primary winding connected in series with a high-current circuit and a secondary winding connected to measurement or protection devices. The high current in the primary winding induces a proportionally smaller current in the secondary winding, typically standardized to 5A or 1A, enabling safe and accurate current monitoring.
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What is the transformation ratio and why is it important?
The transformation ratio is the proportional relationship between the primary winding current and the secondary winding current. It is critical because it allows high voltages and currents to be safely reduced to measurable levels, protecting both personnel and connected equipment from dangerous electrical conditions while maintaining measurement accuracy.
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Why should the secondary winding of a CT never be left open circuit?
Leaving the secondary winding open circuit while the CT is energized is extremely dangerous. Without a load on the secondary side, all the magnetic flux builds up in the core and generates an extraordinarily high voltage across the open terminals. This can damage the insulation, destroy connected equipment, and create serious safety hazards for personnel. Always ensure the secondary circuit is closed or short-circuited before disconnecting any measuring devices.
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What accuracy grade do these current transformers use?
These current transformers are rated at Accuracy Grade 0.5, which is suitable for precision energy metering and measurement applications. This grade ensures minimal measurement error and high linearity across the rated current range, making them ideal for industrial billing, monitoring, and power quality analysis.
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What current ratings are available in the CTY series?
The CTY series offers four models to accommodate different current requirements: CTY-45 (100A/5A), CTY-65 (250A/5A), CTY-80 (400A/5A), and CTY-100 (630A/5A). All models feature a 1-meter lead length and are designed for standard industrial applications requiring a 5A secondary output.
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What is the overload current specification for the CTY series?
The CTY series current transformers support an overload current of ≥1.2% of the rated current (ln). This means the transformers can safely handle momentary overcurrent conditions beyond the nominal rating without compromising accuracy or causing damage, ensuring reliable performance even in fluctuating load environments.