Meet the Cores

At the heart of a current transformer is a slab of magnetic material known as a magnetic core. to put it simply, the measurement mechanism wouldn't work without a magnetic core.

Enveloped by two upper layers of insulation and secondary windings, the magnetic core emits the magnetic field necessary to generate electromagnetic energy. Through the Hall Effect, the current transformer enables a hooked measuring device like an ammeter or voltmeter to get accurate readings. Solid and split-core transformers are known to employ magnetic cores.

Although not the most magnetic metal on Earth, iron is commonly used as a magnetic core material. Aside from its well-known magnetic properties, iron can handle high power outputs rather well, making it ideal for non-measurement functions as well. An iron core may also be any one of these kinds of alloys designed for optimum performance.

• FeSi core – The most affordable of its kind but rather unwieldy, apart from its poor performance at low currents. Commonly used for protecting power grids with high currents.
• FeNi core – The best there is, although the most expensive. Prevalent in current transformer systems, especially for laboratory applications where high accuracy is a must.
• Ferrite core – Once considered low quality for their poor magnetic permeability, this core has been considerably improved by technology. Their high performance for low cost also has utility services thinking about bigger ferrite core transformers.