Transformers 3 (The Dark of the Moon ) Quick Scene

Current transformers occupy a vital role in the scheme of measurement and protection of any electrical installation. Therefore, it is essential that the selection of the CT is made by the number of relays and meters connected to it and complete knowledge of the application.. A current transformer with the wrong load rating or the wrong class of accuracy would seriously compromise the performance measurement and protection system. Calculation of load current transformers. The mass of a current transformer is indicated in its Nameplate. The burden is assessed in VA. such as 15VA or 25 VA. The VA rating indicates the load on the transformer may have. Transf?mat? is the current that is connected to an instrument for measuring or protective relay system by means of wiresVA load the device's data sheet can be supplied by manufacturer. The sum of the total burden and the burden of resistance wire connected devices. part of the inductive wire impedance term is usually neglected as small. The burden of a current transformer can increase over time as the resistance of the cable that connects may slightly increase with age, changes in temperature and loosen the connection. Hence the current should never be loaded to 100% of its capacity. Current Classification TransformersDepending on their application, they can be classified into transformers measurement and protection transformers. Measuring transformers having a high accuracy. However, they have a low saturation point. They are deliberately designed so that the measuring instruments are not damaged by high currents in error. During a failure, as the transformers be saturated and the output remains within the range of measurement tools. Measuring transformers are divided into 0. 1.0. 3, 0. 5, 1. Values ??indicate the percentage error of the nominal primary current. Thus, 100 / 5 transformer with 0. 3 will have an accuracy error of less than 0. 3 when a current of 100 A Passes through the primary. Current transformers used for protection are less accurate compared to measuring current transformers. They have a very high saturation limitTransformers are classified as protection 5P10, 10P10, etc.. The first letter in the notation indicates the maximum percentage error. The last number Indicates the number of times the Rated current. This 5P10 transformer showing the maximum error of 5% to 10 times rated current. Click here for more of such articles
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