Current Transformer Construction and It's uses

Current Transformer

A current Transformer is a current measuring device used to safely produce low currents that accurately represent high currents. The current Transformer is a Closed-loop instrument. Simply we can say calculating and measuring current using a current transformer. it consists magnetic hollow core around the secondary winding which is the output of the Current Transformer.

In the picture shown above Current Transformer's basic principle when a high current passes through the hollow core with the help of the Main Primary Conductor then magnetic field induced and secondary winding wounded on the hollow core thus the current will be flow in the secondary winding which is the output of current transformer. The current flow of the primary winding is proportional to the secondary winding. Basically.

current transformer is a step-up transformer. A current Transformer is usually rated 5A or 1A. , It is manufacturing different ratios like 60:5,100:5,200:5,1000:5, etc. The current ratio is indicated to represent the range of the current transformer. For example of  the current transformer given ratio is 1000:5. Here given I1 = Primary Current 1000A and I2 = Secondary Current 5A it means 1000A flow

on the primary circuit would produce 5A  on the secondary winding.

Types Of CT

A current transformer comes in various sizes, shapes, and ratings.

• Solid core
• Split-core
• Clamp on style 

Solid Core current transformer is commonly used for metering and protection of the switchboard, the panel board, and switchgear.

Split Core Current Transformer is generally used for temporary applications like power quality and instrumentation.

Clamp-on Current Transformer is also used for temporary applications like power quality and instrumentation.

Split core and Clamp-on CT is used in Low and Medium Voltage

FAQ

What is the use of CT and PT?

The current Transformer is a step-up transformer that is used for the measurement of current and protection. A potential Transformer is a step-down transformer that reduces  high-voltage

 into low voltage.it is used for operation and measurement. 

Why CT is short-circuited?

Current Transformer is a step-up transformer that the reason short-circuited because secondary winding has a high voltage which can damage CT.

Why CT is earthed?

Current Transformer induced high voltage on the secondary winding so needs to be grounded for the protection of the circuit.