CT Ratio Calculator, Formula, CT Ratio Calculation

CT Ratio Calculator:

Enter the values of primary current, Ip(A) and secondary current, Is(A) to determine the value of CT ratio, CT.

 Enter Primary Current: A Enter Secondary Current i: A Result -Current Transformer

CT Ratio Formula:

The Current Transformer (CT) ratio is the ratio of the primary current (high current) to the secondary current (lower current) in a current transformer.

A current transformer is designed to produce a scaled-down but proportional current in its secondary winding, relative to the current flowing in its primary winding.

The primary of a CT is often just a single turn (or a few turns) through which the high current to be measured flows. In many cases, the wire carrying the current serves as the primary winding itself.

The secondary winding consists of many turns of fine wire, wrapped around a core that is magnetically coupled to the primary conductor.

The core of the CT is made from materials with high magnetic permeability, facilitating the efficient transfer of the magnetic field from the primary to the secondary winding.

CT ratio, CT is calculated by dividing the primary current, Ip(A) in amperes by secondary current, Is(A) in amperes.

CT ratio, CT = Ip(A) / Is(A)

CT = current transformer.

Ip(A) = primary current in amperes, A.

Is(A)  = secondary current in amperes, A.

CT Ratio Calculation:

1. Calculate the primary current if the CT ratio is 200:1 and the secondary current is 10 amperes.

Given: Is(A)  = 10A, CT = 200.

CT ratio, CT = Ip(A) / Is(A)

Ip(A) = CT * Is(A)

Ip(A) = 200 * 10

Ip(A) = 2000A.

1. Find the CT ratio if the primary current is 1500 amperes and the secondary current is 5 amperes.

Given: Is(A)  = 5A, Ip(A) = 1500.

CT ratio, CT = Ip(A) / Is(A)

CT = 1500 / 5

CT = 300.