Power transformer vector designations 4

[don01]

We have a list of suitable transformers for our job but the vector designation has us scratching our heads.
What does "Dyn11" mean. we assume
"D" = delta primary
"y" = star secondary with nuetral

but what the is "1" or "11"?

knowing we make look a little sheepish but thanks in advance

 

[unclebob]

Look at the vector diagram and compare the angle between H2
and X2. There is a 30 degree shift, counterclockwise, (H2 vector is the reference). If you could put these vectors on a clock, H2 would be at 12 hour and X2 at 11 hour. That 11 is the number you have in Dyn11.

If the angle is 30 degree, clockwise, X2 is on the 1 hour spot, and you get Dyn1.

Likewise with delta-delta or y-y groups. You can have
Dd0 or YNyn0, if there is no angular shift, or Dd6 or YNyn6
when you have a 180 degree shift, with X2 on the 6 hour position. I


Easy to get but hard to explain when English is not your native language...

 

[cuky2000]

See the enclose link

http://cuky2000.250free.com/Dy_IEC_Vector_Group.jpg

Paraphrasing Yogi Berra, engineering is 90% technical and the other half is administrative.

 

[unclebob]

I guess a picture worth a thousand words!

 

[waross]

I haven't seen you here for awhile, cuky2000. Good to see you back.
respectfully

 

[don01]

unclebob & cuky2000
Thanks guys - a collective "ahhh yehhh that's right" has eminated out of the office and now there are dull thud sounds as reference books hit the desks.

your replies really appreciated and have stimulated a lot thinking here

Don