Answer / kaustubh

if we known the pesentage of impedance then by using this
formula we can calculate the fault Lavel.

fault lavel in MVA= Rated KVa/% of Impedence

OR

Fault Lavel= 1.732xFault Currentx Rated Voltage

Answer / gopal

fault lavel in MVA= Rated power/% of impedence


or

Fault Lavel= 1.732xFault currentxRated Secondry Voltage

Answer / mukul

Dear friends above answer is wrong when you are using
transformer KVA in you calculations then pf is not required
the above answer can be corrected by omitting pf from this calcs

Answer / amar singh.

fault level depend on system impedance
full load current*100
Trasformer fault level= ----------------------------
%impedance of the transformer

Answer / pankaj

THERE IS A SIMPLE CALCULATION IF ASSUMING INFINITE SOURCE
BUS THE MAX LEVEL OF FAULT AT LT SIDE OF A 11/0.433 5%
1000KVA TRANSFORMER CAN BE CALCULATED AS:

KVA*100/SQRT3*433*Z% kAMPS

1000*100/1.732*433*5 = 26.7kAMS

Answer / k n naidu

hi,
Calculation of fault level of a distribution net work of
complex in nature manually is laborious. Use network
analyser for simulating the network and fault at the
required bus to get the fault current.
for manual calculation use the MVA method which is
simple and gives fairly acurate results

Answer / leonard

Fault level = Rated Voltage / system impedence (up to that
point)

transformer impedance can be calculated using the
following formula:

Z(transformer)=(Vsq*Z%)/(P*100)

where
Ztransformer is the source transformer impedance, in ohms;
P is the power of the transformer, in volt amperes;
Z% is the rated short-circuit impedance voltage of the
transformer, expressed as a percentage.

Answer / abhi

Fault level = (Rated power of transformer*100)/(percentage
impedance of transformer + imp of subsequent equipments)

Answer / jojo

rated capacity of transformer divide by its transformer
impedance.

Answer / avatar

When deciding the fault levels, isnt there a time component
as well? I have seen the fault levels being designated
as "350 MVA @ 1 sec". What does this mean? Please help.

what is the earth resistance ?

5 Answers   Bhel, Cummins,

What is meant by Low Resistance Cable and High Resistance Cable.

0 Answers  

What is the purpose of REACTOR in GIS substation?

1 Answers  

How to design the blower for motor? how to two blowers connected in motor?

1 Answers   Ashok Leyland, TATA,

what is main parts of alternator.

3 Answers   HP,

What is the difference between Derived earth Fault and measured earth fault.How it works.

1 Answers  

can we synchronize star system generators with delta system transmission line ? and how ?

0 Answers  

Why 268hp induction motor taking different current in three different phases? (In which two phase having same current and one having higher value compare to other 2 phases.)

1 Answers  

what is the difference between ground, earth and neutral?????????....

1 Answers  

why do the alternator doesnt have open circuited windings in armature???

1 Answers  

What is ignitor and why it is use in Hpmv lamp ?

2 Answers  

What is the type of feedback used in an op- amp schmitt trigger?

0 Answers