Answer / ambrish

Pl. show the standard formula to check vector group tst for
any type of transformer.

Answer / raj

the above answer is correct but suppose a newly transformer
has come on the site ?
and nothing is written on the transformer how v will do the
vwctor test for that any one will explain that

Answer / tansford

Superimpose the HV & LV vectors with 1U & 2U as common it
clearly shows the relation between the phasors
Every vector group will have a different relation &
equation to be evaluated

Answer / raj_singh_0376

Procedure of vector group test of transformer


Let’s have a YNd11 transformer.

1) Connect neutral point of star connected winding with earth.

2) Join 1U of HV and 2W of LV together.

3) Apply 415V, three phase supply to HV terminals.

4) Measure voltages between terminals 2U – 1N, 2V – 1N, 2W – 1N, that means voltages between each LV terminal and HV neutral.

5) Also measure voltages between terminals 2V – 1V, 2W – 1W and 2V – 1W.

For YNd11 transformer, we will find,
2U – 1N > 2V – 1N > 2W – 1N
2V – 1W > 2V – 1V or 2W – 1W

Answer / ponnudura

can anyone say me hoe to draw vector group and what is the
use of different vector group and its application plz

Is This Answer Correct ? 17 Yes 8 No submit
srinivas

Answer
# 8 1.1U1V1W-which is primary -Delta Connection
2.2U2V2W- Which is secondary-Star connection
3.join 1U& 2U terminals
4.Supply 1U-1V-1W 440v Measured
a.1U-1V
b.1V-1w
c.1W-1U
d.1W-2W
e.1V-2W
f.1V-2V
g.1W-2V
h.1U-2N
i.1V-2N
TO CHECK
1.1V-2W=1V-2V
2.1W-2V>1W-2W
3.1U-1V=1V-2N+1U-2N
From above check(1,2) the vector group of transformer is
verified

Answer / balaji

1) Can i know why we are making short of any phase during vector group test ?
for Example R-r,Y-y Like that
2) while doing the vector group why the neutral earth should be removed ?

How does frequency affect KVA rating of a transformer? If a 500 kva, 500 to 250 v, 60 hz t/f used in Canada is to be operated on 50 hz in Europe frequency then how will its KVA rating change? a-increase b-decrease c-remains same

1 Answers  

we need a ntpc previous papers

0 Answers  

Can a transformer be used as voltage or current amplifier?

3 Answers   BPDB, REB, Riaz,

Why we use cosine angle for calculating power factor not in sine angle ?

4 Answers  

how to difference between the HT&LT cables

1 Answers   L&T,

Trafo ratio is 11kV/6.6kv,Vector group is YND11. What will be the effect if secondary is used for earthed system.

0 Answers  

What is the main difference between power transformer and Distribution transformer?

9 Answers   APTransco, Bhel, NTPC,

why rating of motor in HP?

11 Answers  

Why we use stones in switchyard?

3 Answers   Havells, L&T,

Dear all i want to know FEWA Electrical Supervisor Licence test Previous Year Questions ? If any body know please send to me shibin_75@yahoo.com

1 Answers   FEWA,

How to calculate VCB rating for 33KV ,25 MW Power line?

0 Answers  

please send me jindal previous aptitude and technical question and answer.my email id is deep_raj@live.com

0 Answers