What is a Current Transformer? Where is it used?
Safety and control are very important in electrical systems. Measuring, monitoring and intervening when necessary in high currents ensures the healthy operation of these systems. At this point, the current transformer appears as a very important part of the circuit. What is a current transformer? Let’s try to explain why a current transformer is used, the transformer operating system and frequently asked questions in the rest of our article.
Current Transformer (CT) is a special measuring transformer that converts high currents into measurable, low values in electrical circuits. It is generally used for measurement and protection purposes. Its main purpose is to allow for a safer measurement of the high current passing through the main circuit, rather than directly measuring it.
To explain with an example, it can be very dangerous to monitor a 1000 ampere current directly with a measuring device. However, a current transformer can reduce this value to, for example, 5 amps, ensuring the safety of both devices and people.
How Does a Current Transformer Work?
A current transformer actually consists of two windings:
- The primary winding carries the high current flowing through the main circuit.
- The secondary winding creates a smaller copy of this current induced by the magnetic field.
Thanks to this system, depending on the transformer ratio (for example 1000/5), a lower version of the high current in the primary circuit is sent to the measuring or protection device.
Where is a Current Transformer Used?
Current transformers have a very wide range of uses. Here are some common examples:
- Electrical panels and meter systems
- Transformer centers
- Industrial facilities and production areas
- Energy distribution companies
- Detecting overcurrent conditions when used with protection relays
- Consumption monitoring and reporting with energy analyzers
In short, current transformers can be used wherever electric current passes.
Types of Current Transformers
There are different types of current transformers depending on the purpose and need. Here are some of the most well-known types:
- Measurement Type Current Transformer: It is connected to measuring devices such as ammeters, voltmeters or energy meters.
- Protection Type Current Transformer: It detects situations such as overcurrent in electrical systems and triggers protection relays.
- Toroidal Current Transformer: These ring-shaped transformers are usually placed around cables or busbars, and are easy to install and compact.
- Split Core Type Current Transformer: It allows installation without disconnecting the cable connection in existing systems.
- Differential Current Transformer: It is used to detect grounding leaks.
Why Should Current Transformers Be Used?
- Safety: It is dangerous to measure high currents directly. Current transformers eliminate this risk.
- Accuracy: The performance of electrical systems depends on accurate measurements.
- Protection: It protects the system in cases such as sudden load changes or overcurrent.
- Economy: Measuring devices do not need to be resistant to high currents.
Frequently Asked Questions (FAQ)
What is the difference between a current transformer and a voltage transformer?
While a current transformer is used to measure current, a voltage transformer is used to reduce high voltages to measurable levels.
Why should the secondary end of a current transformer not be short-circuited?
If the secondary circuit remains open, high voltages can occur in the transformer, which can harm both equipment and personnel.
Can a current transformer work alone?
No, current transformers usually work with measuring devices or protection relays.
What should be considered when choosing a current transformer?
Factors such as primary and secondary current ratio, accuracy class, purpose of use (will it be used for measuring or protection purposes), and physical installation type should be taken into consideration.
We also tried to examine frequently asked questions from users under this heading. If you have additional questions, you can always reach us.
Etiketler: What is a current transformer? Working principles of a current transformer, Where is a current transformer used? What are the differences between a current transformer and a voltage transformer? What should be considered when choosing a current transformer?