What are the functions of current transformer?

Measurements of electric currents


A current transformer allows high values of a.c. current to be measured using an ammeter designed to measure lower-values of a.c. current. At the same time, it electrically isolates the primary circuit from the secondary circuit -essential if the primary circuit is part of a high-voltage system. CTs are also used to monitor primary currents for the operation of high-voltage protection relays.