What does 5P10 mean in CT?

It means the maximum permissible error will be 5% 20 = Accuracy limit factor indicates that the CT will sense the current with the specified accuracy even with 20 times of its secondary current flows in the secondary.

What is meaning of 5P10 in current transformer?

Accuracy Limit Factor of Current Transformer is a very important factor while selecting a CT for protection purpose. Let us consider a CT of ratio 200/5 A, 5P10. This CT will maintain its measurement accuracy of 5% over 10xrated primary current i.e. 2 kA. This factor of 10, is called Accuracy Limit Factor.

What does it mean by 5p20?

5p20 means that. there will be error of 5% when the primary current is 20 times. For example, if. the ct is 1000/1 , then in case of fault, when the fault current is 20000 A, then. the secondary current is 20 A +/- 5%.

What is the difference between 0.2 and 0.2 S Class CT?

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. But, the declared accuracy is guaranteed only between 100% & 120% rating.

What is class1 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.

What is Alf CT?

A “protection” current transformer (CT) must saturate sufficiently high to allow a relatively accurate measurement of the fault current by the protection whose operating threshold can be very high. Current transformers are thus expected to have an Accuracy Limit Factor (ALF) that is usually fairly high.

What is knee point voltage?

The knee point is defined as the voltage at which a 10% increase in applied voltage increases the magnetizing current by 50%. For voltages greater than the knee point, the magnetizing current increases considerably even for small increments in voltage across the secondary terminals.

What is 0.5 S Class CT?

Class 0.5 means that the accuracy is 0.5% of the reading under full load and unity power factor, similar to 0.5% FS above, yet sets a standard for accuracy under lower (typical) loads and different power factor. Table 1 shows the levels of Class 0.5, according to IEC 62053-11.

What is CT accuracy class 0.2 S?

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.

What is 0.2 S Class CT?

What is burden of a CT?

The burden is the termination impedance of the measuring instrument. The measuring instrument can be an analog or digital energy meter, a data logger or a recorder. Technically, the total burden for a CT is the internal winding resistance, the connecting lead resistance and the measuring instrument input resistance.

What does 5p10 stand for in a class?

5P10 class CT: P stands for protection class. If the primary current is 10 times to the rated primary current of the CT, the CT will function perfectly, within the rated composite accuracy class 5 %.

What’s the difference between P, M, and 5p10?

P is designation for protection. 5P10 means that the CT will have max of 5% inaccuracy when the current of 10 times reated current of CT is experienced. M is designation for metering.

What is the difference between 5p10 and 10b50?

P is designation for protection. 5P10 means that the CT will have max of 5% inaccuracy when the current of 10 times reated current of CT is experienced. Never seen or heared of 10B50. The …B50 part is a meausre of the maximum burden the CT can carry and still maintain accuracy. ANSI C57.13 is the relevant guide for instrument transformers.

What is the meaning of 5p20 or 5p10 for an instrument transformer?

Similarly 5P10 can be explained as CT will sense the current with the specified accuracy of 5% even with 10 times of its secondary current flows in the secondary. For example, if the CT is 1000/1, then in case of fault, when the fault current is 10000A, then the secondary current is 10 A +/- 5% Previous: About Capacitor Voltage Transformers