What is CT accuracy class?

What is CT accuracy class?

Accuracy Class of Current Transformer The accuracy class or simply class of measuring current transformer is 0.1, means the maximum permissible limit of error is 0.1%, more clearly, if we try to measure 100 A with a 0.1 class CT, the measured value may be either 100.1 or 99.9 A or anything in between these range.

What IEC 60044?

IEC 60044-1, 1.2 Edition, February 2003 – Instrument transformers – Part 1: Current transformers. This part of IEC 60044 applies to newly manufactured current transformers for use with electrical measuring instruments and electrical protective devices at frequencies from 15 Hz to 100 Hz.

What is the meaning of accuracy class 0.5 S?

A power meter declared as featuring 0.5% FS accuracy means that its inherent margin of error is half percent of the full scale. For example, if the full scale of a meter is 50A, its maximum error is 0.25A. This is known as “Accuracy Class”.

What is CT accuracy class 0.2 S?

High measuring accuracy The very high 0.2s accuracy class guarantees maximum metering, even with low loads. An 0.2s accuracy class means that the measurement has an error rate of 0.2% over a range of 20 to 120% of the nominal current (In) and at a specific accuracy above 1% of In.

How do I know if my CT class is accurate?

The CT Accuracy Class is listed on the label or the nameplate of the CT and is comprised of three parts: rated ratio accuracy rating, class rating, and maximum burden (Figure 2). Rated Ratio Accuracy Rating is a number which is the rated ratio expressed as a percent.

What is the class of CT?

The class designation is an approximate measure of the CT’s accuracy. The ratio (primary to secondary current) error of a Class 1 CT is 1% at rated current; the ratio error of a Class 0.5 CT is 0.5% or less. Errors in phase are also important, especially in power measuring circuits.

Is standard for current transformer testing?

This standard basically applies to current transformers with separate windings, but where appropriate, it will also apply to auto-transformer type current transformers. Indian Standards given in Annex A are necessary adjuncts to this standard. 3.0 For the purpose of this standard, the following definitions shall apply.

What is accuracy class C3?

C3 (0.0230%) – accuracy class C3 is the most common found in machine construction. Typical applications include; belt scales, platform scales and other electronic weighing devices. Of the load cells we provide, C3 is the most common accuracy class. To gain OIML approval the load cell must gain an R60 certification.

What is meant by Class 1 accuracy?

The accuracy class provides a nominal accuracy, but there are many cases where the actual accuracy may be worse. For example, an accuracy class 1.0 meter should be 1% accurate under a narrow range of conditions, but may have a 2% error at 1% of rated current and a 2% error from 75%-100% of rated current.

What does the S on the power meter accuracy class 0.2 S & 0.5 s mean?

0.2 and 0.2S refers to the accuracy of the Current Transformer. A 0.2S CT has a much higher accuracy than 0.2. Accuracy class of 0.2 means +/- 0.2 % error. Thus 0.2S & 0.5S class current transformers are used for tariff metering purposes.


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