×
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

The Z (impedance) for Transformers

The Z (impedance) for Transformers

The Z (impedance) for Transformers

(OP)
Hi,
Is there a table or common values for Z, used in short circuit calcs for typical dry type standard transformers. Example 15 KVA, 25,  ... up to 125 KVA. 480v primary to 220v/110v secondary.  Or, does it have to come from the power co. or manufacturer?
Regards,

RE: The Z (impedance) for Transformers

Actual values have to come from the manufacturer. In fact they can provide you some typical values for "their" products.

More defined ANSI/IEEE stadards (for North America) exist for transformer rated 500kVA and greater. For smaller units, I am not aware of any standards ( that does not mean they do not exist), but the Z of smaller transformer varies greatly  between manufacturers and type.

Typically Z of smaller transformer you describe range anywhere between 1.5% to 3%.

RE: The Z (impedance) for Transformers

ANSI (C57.12, I think... I don't have it in front of me) lists "preferred" or "suggested" transformer impedance values.

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