We are going to install 4 MVA, 11 kV /433 volt Distribution transformer in our plant. Can anyone let me know the procedure for vector group testing of transformers.

 

>We are going to install 4 MVA, 11 kV
>/433 volt Distribution transformer in
>our plant. Can anyone let me know the
>procedure for vector group testing of
>transformers.

It appears from your question that the transformer would be used in secondary distribution system. In such cases, it is usually a Pri. Delta/Sec. Y Transformer. For this, possible vector groups can be Dy1 (30 degree lag) or Dy11 (30 degree lead).

In any case, you can find the vector group on the name plate of the transformer. This is of practical use only if you want to operate transformers in parallel. For stand-alone transformers feeding a section, vector group is not a consideration.

You may please be specific, why you want to test the vector group.

 

Thiragusriram... is the xfmr new? Or is it being reloaded?

Regards, Phil Corso

 

As per name plate the vector group is Dyn11 only, I want to confirm the same by testing.

Sriram

 

Sir,
This is a new transformer. I want to confirm the vector group mentioned in the name plate.

Sriram

 

Sriram... do you intend to use a commercially available transformer testing instrument? Or do it the old fashioned way?

Regards, Phil Corso

 

Mr. Corso,

I'll bite. What is "the old fashioned way"?
IPI

 

Vince... although the commercial instrument may cost a few grand, the "OFW" needs only a short length of cable, a multi-phase power source, a DMM, knowledge of vector math, and last, but not least, a small piece of chalk (any color will do!)

Regards, Phil

 

Sir,
I would like to follow OFW only.

Sriram

 

Sriram... contact me off-list:

Phil Corso (cepsicon [at] aol [dot] com)

 

> We are going to install 4 MVA, 11 kV /433 volt Distribution transformer in
> our plant. Can anyone let me know the procedure for vector group testing of transformers.<pre>
ANS : you 4MVA TRANFORMER 11 KV /433 V
1) short the R phase LV and HV with Insulated wire
2) give the voltage 433, 3 phase HV side
3) you will get 17.047 v LV side between phases
4) consider R,Y,B on HV noted Side
5) Consider r , y, b, n LV side
6) Find out Volatage as per equation
yY=bY
Rn+Yn=RY
7) If the equation is right then your transformer is Dy11 vector group</pre>