Current Transformer – How, Why, Benefits, & Types

by Sanjeev Yadav SEO Consultant

Instrument transformers can be of different types and among those, current transformer is a popular type which is used along with a range of measuring devices. The devices are used to measure if the subordinate current is proportional with the main current or not. The measurement should be perfect i.e. a zero angle deflection.

How CT works?

A current transformer works similarly to a power transformer. Their basic working principle is same. The current transformer too has primary and secondary windings. When AC current passes through the primary winding, it produces an alternating magnetic flux. The flux becomes responsible for encouraging the AC current to move towards the secondary winding.

Why current transformer is used?

Current transformers are used to serve multiple purposes such as –

• Covering relays of currents are protected with the use of a current transformer, especially the magnitude of which current relays’ are proportional to that of the power circuit. You cn identify a massive drop of magnitude.

• The covering devices and the high magnitude supplies have no direct connection in between them. This is the key reason why covering devices maintain power supply to those devices only which are having magnitude proportional to the power contained in them.

• A current transformer isolates the covering devices from the high voltage electric circuits.

Benefits of using current transformers –

• Very high current can be measured with it.

• The measurement of the current transformer’ capacitance, inductance and resistance do not influence its final reading. Pure inductive coils are not used in preparing the primary and secondary windings; still a current transformer has C, L and R parameters.

• For a high voltage system it is important to connect the ammeter inside the secondary winding so that the power circuit has no connection with the measuring current.

• Get a single piece from the current transformer manufacturers for use and this will be enough to run multiple numbers of measuring instruments.

• Current transformers can be used to measure the total volume of power consumption in any electric circuit.

Current transformer – Types:

You can get CT according to the application from any reputed current transformer suppliers in the industry. The suppliers and exporters can provide any desired number of CTs to any part of the globe. So, here is how many types of current transformers are available.

Normally, current transformers are of two kinds –

1. Measuring CT – these kinds of CTs are used for measuring energy, power and current. Usually such types of CTs are used in combination with other measuring tools.

2. Protective CT – these kinds of CTs are used with other protecting equipment such as relays and trip coils.

And, among these current transformers, they can also be classified separately depending on their functionalities.

• Window type – these types of CTs contain no primary winding and has only a secondary winding which remains placed around the conductor through which the current flows. The current flow generates electric field to encourage current flow.

• Wound type – these types of CTs contain a single ore primary winding.

• Bar type – these types of CTs’ integral part has a bar made of suitable material and size.