0
in substation protection
To be connected to unit protection relays (i.e. differential, REF, Dist., etc.)
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How do you determine vkp and rct for class x current transformer given example of 8005a 15va class x ct?
RCT is Secondary resistance of Current transformer it depends on Design.
How do you calculate knee point voltage?
Step 1: calculating knee point voltage Vkp Vkp = {2 x Ift (Rct+Rw)}/ k Vkp = required CT knee point voltage Ift = max transformer through fault in ampere Rct = CT secondary winding resistance in ohms Rw = loop impedance of pilot wire between CT and the K = CT transformation ratio Step 2: calculate Transformer through fault Ift Ift = (KVA x 1000)/(1.732 x V x Impedance) KVA = transformer rating in kVA V = transformer secondary voltage Impedance = transformer impedance Step 3: How to obtain Rct To measure when CT is produce Step 4: How to obtain Rw This is the resistance of the pilot wire used to connect the 5th class X CT at the transformer star point to the relay in the LV switchboard. Please obtain this data from the Electrical contractor or consultant. We provide a table to serve as a general guide on cable resistance. Example: Transformer Capacity : 2500kVA Transformer impedance : 6% Voltage system : 22kV / 415V 3phase 4 wire Current transformer ratio : 4000/5A Current transformer type : Class X PR10 Current transformer Vkp : 185V Current transformer Rct : 1.02½ (measured) Pilot wire resistance Rw : 25 meters using 6.0mm sq cable = 2 x 25 x 0.0032 = 0.16½ Ift = (kVA x 1000) / (1.732 x V x impedance) = (2500 x 1000) / (1.732 x 415 x 0.06) = 57,968 round up 58,000A Vkp = {2 x Ift (Rct+Rw) } / k = {2 x 58000 (1.02+0.16) } / 800 = 171.1½
What is a private class?
A private class is a class that cannot be directly accesed from outside its outer class, similar to a private variable or method. This means that a private class must always be an inner class, though an inner class can be public or protected instead. For instance, the following is valid and means that any X object cannot directly access the inner Y class. public class X { private class Y{} } The following however is invalid. private class X{}
What is the role of class x after talking ICSE in class XI?
simple ...............................................................................................................................................................................................................................................study
What is the prototype of a copy constructor for a class X?
class X { public: X(); // default constructor X(const X& x); // copy constructor // ... }; int main(void) { X objx1; //normal ctor X objx2 = x1; // copy ctor X x3(x2); // copy ctor }
Ct scanning makes use of?
x-rays.
How do you determine vkp and rct for class x current transformer given example of 8005a 15va class x ct?
RCT is Secondary resistance of Current transformer it depends on Design.
What do radiographs and ct scans use to form images of anatomical?
X-Ray or radiograph
Class px ct?
Class PX is the definition in IEC 60044-1 for the quasi-transient CT formerly covered by Class X of BS-3938, commonly used with unit protection schemes. These are Protection CTs used for Earth fault protection. Knee point voltage is an important parameter for these type of CTs. Shaikh
How are CT scans and x rays the same?
They both use ionizing radiation to make an image.
What do radiographs and CT scans use to form images of anatomical structures?
X-Ray or radiograph
Do scanners have electricity?
Yes. The Ct scan machines produce X-rays. They use low quantity of the X-rays. But still they are the X-rays. X-rays are produced artificially by the use of the electricity as a power source.
What is the name of the scientist that studies CT scans and X-rays?
A radiologist studies CT scans and X-rays.
How are CT scans and X-rays the same?
Both use X-Rays. Difference is X Rays use one single "shot" of radiation, CTs fire much more at you to get different "slices".
What is a class X current transformer?
Class X CTs are special CTs used mainly in balanced protection systems (including restricted earth fault) where the system is sensitively dependent on CT accuracy. Further to the general CT specifications, the manufacturer needs to know: • Vkp - Voltage knee point • Io - Maximum magnetising current at Vkp • Rs - Maximum resistance of the secondary winding
Which is the ray used in ct scan?
The ray used in CT scans is X-Ray!!!
What is the computerized x-ray imaging in the transverse plane?
CT scan
