Understanding AC and DC Current Transformers

When your company needs to monitor electrical usage, one of the more accurate means to do so is to use current transformers. Working for both alternate current and direct current, they provide a way to measure the high voltage currents that are usually used by industrial and commercial firms; they do this by converting the current into a much lower value so it can be measured safely and easily. There are three types of current transformers on the market.

• Wound current transformers– Transformers work by having three parts: a primary winding, magnetic cores, and a secondary winding. Wound current transformers have their primary winding physically connected to the conductor that carries the current. How powerful the resulting current will be is dependent on how many “turns” the winding is wound around the core.

• Toroidal current transformers– This type doesn’t have a primary winding. Instead the current is passed through a hole in the core. This can make it easy to install without any disconnecting done.

• Bar-type current transformers– Similar to toroidal types, it uses the bus-bar of the main circuit as the primary winding instead of having its own. They can also be easily attached to current circuit and are heavily insulated.