The Current Transformer’s Role in a Circuit

Electrical measurements are critical to industries that rely on electricity for production continuity. After all, aside from potential interruptions due to sudden current flow changes, over fusing can lead to fires and increased current flow through the wires. Constant monitoring of the current flow using measuring instruments, such as an ammeter, is imperative in any electrical system.

Unfortunately, most measuring instruments cannot take the current flowing through live wires. Like how electricity can severely injure living things that come into contact with an open electrical source, so does the circuitry inside these instruments burn when subjected to excessive currents. An electrical measuring instrument has to be protected so it can continue to measure alternating current without the risk of over fusing.

This is where a current transformer (CT) becomes very useful. A CT is a type of transformer that can step-down current levels from several thousands of amperes to standard levels that a measuring instrument can take. The CT consists of common components found in a regular transformer, e.g. a core and a coil of wire.

CTs can either be solid or split core. A split core CT, by definition, has an opening along the core where the source wire to be measured can be easily inserted. The wire coiled on the core transfers just enough current to the ammeter to prevent it from getting damaged. This facilitates proper measurements and ensures the device’s safety.