How to determine short circuit capacity of power transformer 2

[eeprom]

Hello,
I am working with a 5 MVA oil filled transformer, and I am trying to figure out how to fuse the equipment on the secondary side in order to properly protect the transformer against short circuit damage. I am looking for documentation which will help me to determine the magnitude and duration of the allowable fault current based on the ratings of the transformer. Can someone point me in the right direction on this?

 

[Zogzog]

OK that is about a million $ transformer, I really think you should hire a PE to determine this. The way you asked the question shows you have little understanding of power systems and seem to be in way over your head.

There are many in this group that could answer your question but I doubt if any one will. Sorry.

 

[Zogzog]

Thought you said 50 MVA, 5 is not a million but easily 6 figures, dosent really matter, you still need to hire a PE.

 

[jghrist]

See IEEE Std C37-91-2000, IEEE guide for protective relay applications to power transformers
Abstract
The protection of power transformers is covered; various electrical protection schemes are explored; and guidelines are given for the application of these schemes to transformers. Alternative detection methods including mechanical, thermal, and gas analysis are discussed.

 

[cranky108]

Transformer protection, as all power system protection is like insurance; How much risk can you afford?

Then again you can put very little protection, and buy insurance.

 

[ijl]

Something to start with:

http://www.skm.com/application_guides.shtml

 

[eeprom]

ijl,
Thanks. The damage curves are what I was looking for.

 

[7anoter4]

good staff ijl!