Answer / siddharth

composit error- it is difference between instataneous
primary current and inst. secondry current multiplied by
turn ratio.
ratio error and phase error is occured due to some primary
current is utilised to magnetise the core.

Answer / raghavendran.r

1) Composite error = [Ip - KIs]/Ip * 100

2) phase error = error or deviation in the phase
displacement of primary and secondary
current.
3) Ratio error = The secondary current is less than the
expected value. The secondary is less in magnitude. This
diffence is known as ratio error.

Answer / karuppasamy

The total error vector (composite error) can be seen as the composition of:
an amplitude error (ratio error), expressed in % and
an angle error, expressed in radians or seconds.
Note that for protection CT's, the angle error is disregarded and only the total composite error is given in %. When examining the equivalent diagram, one would easily conclude that the error current can only be the magnetising current of the CT. Indeed, normally the magnetising current is very low but at the saturation point of the core, 50% increase in magnetising current produces only 10% extra secondary voltage so at saturation the error current rises quickly. Therefore, the property's accuracy and saturation of the core are closely linked. Hense the error vector is allways a reducion in secondary output current; negative error. Positive error is only possible by ratio-turn correction.

Answer / gunasekaran

composite error is combine of the ratio and phase angle
error ratio error deviation from the rated sec current phase
angle error is phase displaceme from primary current it is
+-60sec
suppose 5p20 ct composite error is +-5%
ratio error is +-5% phase angle error +- 60sec

What is the working principle of MIG welding? and its out put Voltage?

0 Answers   L&T,

---

Can any one give an explanation about rating factors of cable? if we are laying the cable on the air with an temp 15 degree then rating factors will be 1.15 and if we are laying the cable on the air an temp 60 degree then rating factor will be 0.76 please describe it and what is the difference between rating factor and derating factor?

0 Answers  

---

Double Busbar Scheme for outdoor switch yard system (132kv) step up power plant Hi friends 1. in this system both busbars energized all the time. 2. what is the meaning of main BB and transfer BB, 3. step up transformer connect main bus bar all the time or both BB connected through DS switch . 4.bus sectionalization means ? thank you.

1 Answers   ABC, Gael,

---

how to calculate busbar size? ex:11000kva main what is the busbar size ?and how to select the correct one

4 Answers  

---

What is the difference between Off line UPS and Line interruptible UPS?

1 Answers   Etisalat,

---

What kind of maintenance is conducted for Transformer

0 Answers   Gulf, UB Engineering,

---

Why we choose 400kv,220kv,132kv,66kv,33kv transmission voltages for transmitting power. Why not other voltage levels.

21 Answers   College School Exams Tests, HC, HCL, Jaypee, JPMorgan Chase,

---

how i calculate the syncrones generator NGR resistance .if we have a 6mw generator line voltage of generator 11kv also line current 393.3 ampere.

0 Answers  

---

what is the main different between distribution transformer and power transformer ?

7 Answers   Sail,

---

what is meant by insulation voltage in cables? explain it?

4 Answers   ABB,

---

why electric shock due to dc is dangerous than that of ac

8 Answers  

---

In single phase ac ups supply when current is measured with tong tester neutral current is found more than phase current.What is the reason?

0 Answers  

---