Industrial Manufacturing

All about current transformers (CT) 

Current Transformers (CT) are used in electrical engineering, and they are used to measure electric currents. CT, along with PT (Potential Transformers) is together known as Instrument Transformers. In order to regulate flow and control the performance of the power grid, Current Transformers are employed widely, and its current rate classically determines it from primary to secondary.

Extra information about current transformer


CT is mostly seen and used in metering and protective relaying in the electrical power manufacturing where they execute the safest obligation of a massive amount of currents, regularly in the presence of high voltages on the circuit.

Another function that the CT has is that it has the power to isolate the equipment used for measuring from the primary circuit, which may contain a very high voltage; this protects the machine from damage and enables it to function accurately.

These devices are often used in the operation of power grids and along with high voltage cables, it allows the current to be measured when needed to ensure everything is running how it should because electricity can be a very dangerous and unpredictable force, it is essential that it is monitored at all times when possible

Factors that improve the current transformer's accuracy

They are like a burden, rating factor, physical CT configuration etc.

Elements of a Transformer

Within a CT, there are two or more conductor windings, each existing on a magnetic core route. To ensure that the CT magnetic conducting quality is high and fills the entire core, a rolled iron in sheets is used. The iron sheets are covered to block the centre from overheating. The primary coil wound around the centre receives energy. Manufactured for accuracy, there are only minor losses of energy between primary and secondary coil windings.

Types of electrical transformers are;

Three phase transformers

Step down transformers

Control Transformers

Power transformers

Dry type transformers

High voltage transformers


It is necessary that the CT is manufactured and conform to certain standards due to their functions and the type of task they are required to perform. There are various applications for CT. Some devices are used to determine the flow in motor or electronic equipment while other in street lighting CT which have tiny footprints are installed on printed circuit boards which are essential for sensing the current overloads.

Huge devices are used in various three-phase systems to determine the voltage, and commercial transformers are used to measure low power currents. Other transformers are used outdoor since they are weatherproof.