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secondary winding of a CT or a PT with their primaries connected to the
lines.
We will now discuss in some details of current and potential transformers.
11.12.1 Current Transformers
A current transformer has very few turns in its primary. The secondary will
have a large number of turns. The secondary winding is closed through an
ammeter of range 0–5 A. Thus, a current transformer is like a short-circuited
transformer having a limited current flowing through the secondary, the
voltage across the primary winding being very small.
The turns ratio,
The nominal ratio,
The transformation ratio,
Since the output current is measured on a 0–5 A ammeter, the current flowing
through the primary winding, which is being measured, can be calculated by
multiplying the ammeter reading by the turns ratio.
