High-Quality F2 Series Current Transformers from Reliable China Suppliers and Factory for Power Systems Monitoring
Product Overview
A CT is powered by electromagnetic induction and consists of a main winding (few turns, connected in series with the high-current circuit) and a secondary winding (many turns, coupled to safety or measurement devices). The primary winding receives a large current whereas the secondary winding, which is typically standardized to 5A or 1A for most industrial purposes, receives a proportionately low current. This proportionality, sometimes referred to as the transformation ratio, ensures accurate current measurement without exposing personnel or equipment to potentially dangerous voltages.
High Precision
Essential for accurate energy metering in industrial applications.
Strong Linearity
Prevents measurement distortion across the full operating range.
Insulation Strength
Maintains high voltage isolation between primary and secondary windings.
Important Safety Notice: While using a CT, the secondary winding should never be open-circuited. An open circuit may result in dangerously high voltages that could harm equipment and personnel.
In conclusion, because they provide precise current monitoring and excellent fault protection, current transformers are critical to maintaining the reliability, efficacy, and safety of modern electrical systems.
Technical Parameters
| Type | Main Loop Current | (mm) Outline Size | |||||
|---|---|---|---|---|---|---|---|
| F2-1025 | 162 | 71 | 28 | 155 | 100 | 25 | |
| F2-1435 | < 250A | 202 | 28 | 195 | 140 | 35 | |
| F2-1835 | < 400A | 242 | 82 | 28 | 235 | 180 | 35 |
| F2-2245 | < 630A | 282 | 92 | 28 | 275 | 220 | 45 |
| F2-3045 | < 1250A | 363 | 92 | 28 | 355 | 300 | 45 |
| Rated Primary Current: 1A | Rated Second Current: 0.5mA | ||||||
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Frequently Asked Questions
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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 measuring or protection devices). The large primary current induces a proportionally smaller current in the secondary winding, enabling safe and accurate measurement.
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Q
What are the standard secondary current ratings for industrial CTs?
For most industrial applications, the secondary winding of a CT is standardized to either 5A or 1A. These standard ratings ensure compatibility with a wide range of measurement instruments, protection relays, and energy meters used in industrial environments.
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Q
Why should the secondary winding of a CT never be left open-circuited?
When the secondary winding of a CT is open-circuited while the primary carries current, all of the primary magnetomotive force drives the core into deep saturation. This produces dangerously high voltages across the open secondary terminals, which can damage insulation, destroy connected equipment, and pose a serious safety risk to personnel. The secondary should always be connected to a load or short-circuited when not in use.
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Q
What does the transformation ratio mean in a current transformer?
The transformation ratio refers to the proportional relationship between the primary current and the secondary current in a CT. For example, a CT with a ratio of 1000:5 will produce 5A in the secondary when 1000A flows through the primary. This ratio ensures accurate scaling of high currents to safe, measurable levels without direct contact with high-voltage circuits.
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Q
What main loop current ranges are supported by the F2 series CT models?
The F2 series covers a wide range of main loop currents to suit various industrial needs. The F2-1435 supports up to 250A, the F2-1835 supports up to 400A, the F2-2245 supports up to 630A, and the F2-3045 supports up to 1250A. All models share a rated primary current of 1A and a rated secondary current of 0.5mA.
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Q
Why is insulation strength a critical characteristic of current transformers?
Insulation strength is critical because it maintains electrical isolation between the high-voltage primary winding and the low-voltage secondary winding. Without adequate insulation, dangerous high voltages could transfer to the secondary side, endangering measurement instruments, protection devices, and operating personnel. High insulation integrity is especially important in medium and high-voltage power systems.