×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Transformer fault current

Transformer fault current

Transformer fault current

(OP)
General system fault level is specified at 35kA

Part of installation involves small isolation 50kVA Tx's before dist boards for lighting & small power etc. (415/433V)

What is best way to calculate expected max fault level to be expected at secondary terminals? Z = 6%

I am looking to rate the DB's at around 16kA

Any help would be appreciated.

Thanks in advance
Peter

RE: Transformer fault current

50kVA 3Ø transformers, 415V secondary voltage, 6% impedance, connected to an infinite bus on the primary will have 1159A of fault current on the secondary.

50/(0.415*sqrt(3)*0.06)=1159A.

I wouldn't worry about complicating the calculation by trying to include a less than infinite source on the primary.

RE: Transformer fault current

David
I used a single phase transformer.
50kva/0.415 = 120 amps/0/06 = 2000 amps phase to phase and
about 3000 amps phase to neutral.

RE: Transformer fault current

(OP)
Thanks Guys

Very helpfull

Regards
PeterP

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources