fault current calculation at generator and downstream panel

[anbm]

Hi,

I have to use point-to-point method to calculate fault current current and submit to Florida state. How to we calculate fault current at emergency generator and its first downstream panel?

I mean I have standby 250kW, 480V/3PH, emergency generator EG1 which feeds emergency panel 'EDPH' and panel 'EDPH' will feeds ATS1 and ATS2.

They are looking for fault current at EG1 and panel 'EDPH'. ATS1 and ATS2 are also fed out of normal power source which I knew how to calculate the fault current at these points.


Thanks!

anbm

 

[dpc]

So you develop an impedance diagram, showing the generator impedance (sub-transient reactance) and the cable impedances. Then reduce this to an equivalent impedance at each point where you need to know the fault current.

Then calculate the current (I = V/Z)

 

[7anoter4]

Hi anbm
As dpc stated in the above post attached find pls. here is an example
Regards

 

[anbm]

7anoter4,

Can you give me full name of all of variable in the calculation? Thanks!

anbm

 

[7anoter4]

First of all I have to apologize it was not the attachment I intended to transmit. Find pls. attached the actual one.
Regards

 

[7anoter4]

For American Standard [ANSI/IEEE] and USA measure units [awg, feet and so on for cable only] see:

http://www.arcadvisor.com/reference.html

http://ecmweb.com/mag/electric_shortcircuit_calculation_methods/

My opinion: on principle, it is the same.

 

[rbulsara]

anbm:

Buy and read up IEEE Red Book.