Generator Short Circuit Current

[Mohsin Jameel]

Generator of 400 V 1250 KVA shows Max 3 Phase Short circuit current of 19 KA . In my opinion it is the maximum three phase SKA that Generator can produce obviously can produce higher P-G fault being solid ground.

We have 3 Generators in parallel.

My question and confusion is that when we model it in ETAP software its 3 phase fault contribution on ETAP run when considering fault at Main bus comes out to be more than 19 KA. Is it possible that generator with rated/datasheet mentioned capacity of 19 kA can feed 24-26 kA in any case.

Should we need to tune ETAP modelling to restrict fault current to 19 kA or is it possible that generator can feed fault current more than fault current mentioned on its datasheet

 

[FreddyNurk]

Could be a number of things. ETAP might be displaying a peak figure, depending on the particular method that ETAP is using.
At 24-26kA it doesn't sound like multiple sets involved in the calculation if they're all the same size, but that is also a factor.
Another possible factor is that the 1250kVA is a user selected rating whereas the base for kVA values might be something else, although it'd be a big jump in size to get to 24kA.

EDMS Australia

 

[dpc]

Make sure you are not comparing symmetrical fault current with asymmetrical current.

 

[waross]

19 kA RMS = 26 kA peak.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!