×
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

Nameplate Vector Diagrams-overlaying vectors=phase shift?
2

Nameplate Vector Diagrams-overlaying vectors=phase shift?

Nameplate Vector Diagrams-overlaying vectors=phase shift?

(OP)
Am I correct that simply overlaying vectors on transformer nameplates will indicate the phase shift from primary to secondary?  Is this true of all transformers nameplates - Dy5, Dy11, Yd1, Yd5, Yd11, etc...?

For example, a Dy1 vector diagram from one of our 115D/13.8Y transformers - if you overlay the wye over the delta it shows the H1 is leading X1 by 30 deg (CCW rotation & A-B-C sequence).

                     H2                                                      X2
                       .                                                        .
                   .      .                                                  .
                .            .                                            .
             .                  .             X1 .   .   .   .   .   .  
          .                        .                                      .
       .                              .                                      .
    .     .    .    .    .    .    .    .                                       .
H1                                      H3                                X3

On a Dy11 nameplate, the wye would be turned 60 deg CCW (compared to Dy1 vector)?

I appreciate your time answering these kinds of questions.

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

pls try searching the threads in this forum as this topic has been discussed in detail b4.

isoA120

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

or read Thread238-11381 in this forum. It may help u

IsoA120

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

(OP)
I did extensive google and forum search but did not find anything addressing overlaying nameplate vectors to determine phase shift.

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

(OP)
Thanks jbartos.

Dy1 is common to my area.  I seldom get an opportunity to see nameplates on transformers other than type Dy1.

It's good to know that overlapping vectors does indicate leading or lagging phase shift since nameplates don't designate Dy1, Dy5, Dy11, Yd1, Yd5 or Yd11 (I haven't noticed it).  They only show the vector diagrams.

You can quickly know the phase shift by drawing the overlapped vectors.

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

Suggestion: Dy1 is at 1 o'clock and Dy11 is at 11 o'clock, namely, the primary winding of the transformer versus the secondary winding of the transformer. The the CCW or CW rotation plays important role.

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

You don't have to overlay the vectors. A simple multiplication will suffice:

If you multiply the number in the vector group designation by 30 it will indicate the angle by which the primary voltage leads the secondary voltage.

Examples:  Dy1 -> 1 x 30 = 30 degrees
           Dy5 -> 5 x 30 = 150 degrees, etc.

God bless!

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

You are correct about the Dy11 nameplate.  To get the # in the Dy# format, consider the secondary phase that corresponds to the primary phase that is at the top (12 o'clock position).  In your Dy1 example, this would be X2 corresponding to H2.  If necessary, rotate both the primary and secondary diagrams the same amount to get one primary phase at the top.  The clock hour position of the corresponding secondary phase is the # in Dy#.  In your example, X2 is at the 1 o'clock position, so the designation is Dy1.  If X2 were at 11 o'clock, it would be Dy11.  Note that clock hour positions are 30° apart.

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

(OP)
I looked at two Dy1 Transformers today and neither had the Dy# designation on the nameplate.

It may be that manufactures don't list the Dy# on nameplates because customers can connect A-C-B sequence and cause a Dy1 to act as a Dy11.  Just a thought.

mvcjr - without the Dy# on the nameplate you don't have anything to multiply by 30 degrees.

RE: Nameplate Vector Diagrams-overlaying vectors=phase shift?

We have U.S.-made and European-made transformers in our system. In the U.S.-made units only the vector diagram and winding diagram are shown on the nameplate. In the European-made units usually the winding diagram, vector diagram and the vector group designation are shown. Probably due to differing standards?

However, with frequent exposure to vector diagrams you can immediately relate a vector diagram it to its corresponding vector group.

God bless!

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