For example, a current transformer with a ratio of is rated for primary amps at full load and will produce 5 amps of secondary current when amps flow through the primary. If the primary current changes, the secondary current output will change proportionally.
For example, if amps flow through the amp rated primary the secondary current output will be 2. There are several different types of current transformers, each facilitating the step-down and metering of current, but the manner in how that is accomplished can be different. The following explains the characteristics of three main types of current transformers. The wound current transformer has a primary winding of more than one full turn wounded on the core.
The primary and secondary winding of the wound current transformer is insulated from each other consisting of one or more turns encircling the core. Constructed as multi-ratio CTs by the use of taps on the secondary winding. The wound type provides excellent performance under a wide operating range. The toroidal current transformer does not contain a primary winding. Instead, the line that carries the current flowing in the circuit passes through a window or hole in the toroidal transformer.
The bar-type current transformer uses the actual cable or busbar of the main circuit as the primary winding, which is equivalent to one turn. Bar types are available with higher insulation levels and are usually bolted to the current caring device. We recommend that you choose the ratio immediately higher than the maximum measured current In.
The current transformer accuracy is determined by its certified accuracy class that is stamped on the nameplate. For example, a CT accuracy class of 0. To be more explicit, for a primary current of A it is certified to produce a secondary current between 2. The current transformer ratio is specified with the assumption that the primary conductor passes through the window once, but it is possible to modify the ratio by looping the primary conductor through the opening additional times.
Introducing two loops decreases the ratio by a factor of two, yielding a ratio, and three loops provide a decrease by a factor of three, or The primary and the secondary windings are insulated from the cores. The primary winding includes a single turn that carries the full load current whereas the secondary winding includes a number of turns. The ratio of the current in the primary and secondary is called a current transformer ratio. The current ratings in the secondary are 0. Indoor type transformers are applicable in low voltage circuits.
These are classified into different types like wound, window, and bar. Similar to the basic type, wound type includes two windings like primary and secondary. The bar-type transformer includes bar primary with secondary cores. In this type, bar primary is an essential part.
The accuracy of this transformer can be reduced because of the magnetization in the core. Window type can be installed in the region of the primary conductor because the designing of these transformers can be done without primary winding. Before connecting this kind of transformer, the primary conductor should be detached whereas, in split-core, it can install directly in the region of the conductor without separating it.
SF6 insulated type transformers are lightweight when we compare with oil-filled type transformers. The pinnacle tank can be connected toward the primary conductor which is known as live tank construction current transformer. In this construction, small bushings are utilized because both the tank and the primary conductor are at the same potential. For multi-ratio CTs, the split type primary winding is used. Thus taps are arranged on the tank intended for the primary winding so variable current ratio can be obtained by using these transformers.
The transformers ensure your electrical gadgets or home appliances are protected from sudden electrical problems. Contact an electrical professional for more assistance and further information on the differences between current and voltage transformers. Table of Contents. Current transformer. The CT transformer operates under a state close to the short circuit under normal condition The primary winding is installed in series in the current.
Potential Transformers. The majority of American homes use different voltages for various purposes. One of the major differences between CT and PT transformers is their functions. Transformation Ratio. Primary and Secondary Winding. Primary Current. Secondary Side.
Input Value. Secondary Winding Range. In a current transformer, the range is 1A or 5A, while in a potential transformer, it is V. Recommend Reading. Post Views: 13, Twitter Youtube Facebook Linkedin. You Might Be Interested In.
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