Answer Posted / mak

The fault current of a power transformer will depend on the following;
Transformer Rating (in KVA/MVA)
per unit impedence of the transformer (%p.u.)
line/phase Voltage (VL/VP)
the following formula can be used to find the fault current on the secondary side of a transformer
Fault Current = Transformer Rating /(per unit impedance x phase voltage)

The Values of Transformer Rating, per unit impedance & phase/line voltage will usually be mentioned on the transformer rating plate / data sheet
As an example a 500kVA, 11kV/400V/3-Phase/50Hz transformer with 5% p.u impendence will have the following fault levels on the secondary side

Fault level = 500/(5%)=10000kVA


Fault current = 500/(5% x 400 x 1.732) = 14.4 kA

Remember to use 3phase voltage!

what is the difference between single ratio, multiple core and multiple ratio, multiple core ? please explain.

2146

---

how to deside the capacity of chock for drive?

2000

---

is it possible to have dc motors on single chip

1773

---

Describe Non I.S. Earth System and why is it used?

1725

---

Both generator parallel condition shared load equally but one genrator taking ampere more than the other what are all the causes to make like this

1694

---

What is the comparison between 30mA DP RCCB and 100mA DP RCCB and can replace it against 63A MCB

1533

---

In constant power region of 3-phase IM torque-speed characteristics, if frequency increases flux A does not alter B decreases C increases D none of above

2182

---

WHAT IS ELECTRICAL MAINTAINTENCE ?

2001

---

What is the effect of solar radiation on the design of an Isolated Phase Busduct?

2295

---

where reactive power is used

1992

---

Why MCCB is Getting tripped sometimes when there is no load in the Midnight ?

1915

---

Operation of isolators.

1828

---

How to address the servo drive for motor

1948

---

Why are the laminations insulated from each other?

1097

---

what is distribution board?

2259

---