Answer / jaswinder

% impedence is use to determine the max fault current the
transformer is capable of delivering to a downstream short
circuit.
Fault current=FLC*100/%imp.
this fault current is use to cal fault MVA
Fault MVA = 1.732 x fault current x V.

eg: If transformer of 2000kVA,5%imp having flc of around
1200A is use to supply to a motor of same flc carrying
capacity and if the voltage drop at transformer terminal is
more than the permissible voltage drop (+- 10%)during
stating of motor then the above transformer will be of
lower rating hence we have to select the transformer rating
higher than 2000kVA eg:-3000kVA (In other words transformer
having higher SC current capability ).If voltage remain
within the rated voltage of the motor then no oversizing of
tranformer is required.

Answer / akr

hieght of winding effect on impedane

What is transient response?

0 Answers  

---

Why is tan-delta test and capacitor measurement done on alternator?

0 Answers   TD Power Systems,

---

any body,pls tell me how to done relay coordination ? how to coordinate by TCC curve?how to read the tcc curve?

0 Answers  

---

UG cable sizes were specified in sqmm. But practically its not coming to mesure. What's the reason for that? And how they specify the size of the cable?

0 Answers  

---

what is basically a pulse transformer?

1 Answers  

---

For a three phase induction motor, what will be the effect on motor if the neutral of the system is shifted to say 20 deg.?

0 Answers  

---

Why we called L-G fault as line to ground fault why ground? suppose if a line falls on building roof then can we called these fault as line to roof fault? please explain why ground term is used here?

3 Answers   Bhel,

---

the current which flows during lightening is ac or dc,,,,,,,,,,, WHY

6 Answers  

---

What is the bundle conductor?

0 Answers  

---

1. If 8.35%Z means the percentage impedance of 132kV-line from power company, we will like to confirm its base capacity?

0 Answers  

---

What is the function of restraining coil in differential relay? as well as restraining current?

8 Answers   Medical, Siemens,

---

How can we calculate the rating of a transformer suppose if load is 1000KW?Formula?

3 Answers  

---