Nameplate Vector Diagrams-overlaying vectors=phase shift? 2

[Manindemand]

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.

 

[isoA120]

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

isoA120

 

[isoA120]

or read thread238-11381 in this forum. It may help u

IsoA120

 

[Manindemand]

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

 

[jbartos]

Suggestion: Visit

http://leme

http://www.epfl.ch/ME/publications/2002/pcim2002transfos.doc.pdf

http://www.mss.de/eng/stromversorgungen/produkte/pdf/gr3e-inh.pdf

(for page 4)

Also, search for
Phase angles on DYN11 transformers
in this Forum

 

[Manindemand]

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.

 

[jbartos]

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.

 

[mvcjr]

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!

 

[jghrist]

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.

 

[jbartos]

Suggestion: Visit

http://www.siemens.com.mx/PTD/downl...ide/Contents, Introduction, Product Range.pdf

for: page 5/4 for transformer vector group. Notice, that 30deg lag or 30deg lead associated with Yd1 or Yd11 or vice versa is not explicitly stated.

 

[Manindemand]

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.

 

[mvcjr]

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!