e.saravanan


{ City } cuddalore
< Country > india
* Profession * engineer
User No # 22754
Total Questions Posted # 0
Total Answers Posted # 10

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Total Views for My Questions # 0

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Questions / { e.saravanan }
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Answers / { e.saravanan }

Question { Sunflag Steel, 96157 }

How to take Vector group test of Transformer?


Answer

Assumed the transformer vector group is DYn11;
1.1U1V1W-which is primary -Delta Connection
2.2U2V2W2N- Which is secondary-Star connection
3.By connecting terminals 1U& 2U
4.Then three phase Supply is given to 1U-1V-1W
5.By measuring the terminal given below
We get
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
THE BELOW GIVEN CONDITION IS SATISFIED THEN DYn11 IS
CONFIRMED
1.1V-2W=1V-2V
2.1W-2V>1W-2W
3.1U-1V=1V-2N+1U-2N

Is This Answer Correct ?    121 Yes 26 No

Question { Neutech, 93351 }

What core magnetic balance test of transformer?
How to do this test in a three phase Star delta (star-LV,
Delta-HV) transformer?
How to measure and where to measure?

thanks and regards
Austin


Answer

MAGNETIC BALANCE TEST

THIS TEST IS SIMILAR AS OPEN CIRCUIT TEST

PROVIDE THE SINGLE PHASE SUPPLY (BELOW 230 V)TO THE STAR
SIDE OF THE TRANSFORMER BY PROPERLY CONNECTED

1.GIVE SUPPLY TO 2N AND 2U AND THEN MEASURE THE VOLTAGE ON
2N2V AND 2N2W
(i.e)IT SATISFIED THE CONDITION

2U2N=2V2N+2W2N

SIMILARILY THE TEST CONDUCTED ON OTHER TWO PHASES BY SAME
MEANS

(NOTE: NO ONE SHOULD BE STAND ON HIGH VOLTAGE SIDE WHILE
TESTING )

Is This Answer Correct ?    100 Yes 32 No


Question { 8552 }

WHY DIODE IS CONNECTING ACROSS SWITCHES


Answer

Because it opppose the flow of reverse current in the
neutral circuit

Is This Answer Correct ?    8 Yes 0 No

Question { 5779 }

Can anybody tell me how to calculate(formula) earth flat
size(for copper and aluminium).


Answer

THE WEIGHT OF THE EARTH COPPER PLATE IN CALCULATED BY THE
PRPDUCT OF LENGTH ,BREATH, THICKNESS AND DENSITY OF THE
COPPER

Is This Answer Correct ?    4 Yes 2 No

Question { Wipro, 11507 }

what is general test conduted by transformer


Answer

The General test conducted on transformer is
1.Insulation resistance test
2.Open circuit test
3.Short circuit test
4.Double voltage and double frequency test
5.High Voltage test
6.Resistance test
7.Vector group test
8.Magnetic balance test
9.Break Down Voltage test

Is This Answer Correct ?    19 Yes 3 No

Question { UltraTech, 36451 }

How to calculate kva? what is the formula.


Answer

KVA = SQRT(3)X V X I

Is This Answer Correct ?    26 Yes 45 No

Question { 7505 }

I HAVE CONSUMER WHOSE POWER FACTOR IS 65% I WANT TO INCREASE
IT TO 98%.HOW TO CARRY OUT?


Answer

PROVIDE YOUR LOAD IS VERY USEFUL FOR FINDING OUT

Is This Answer Correct ?    4 Yes 6 No

Question { KPCL, 46792 }

which motor is suitable for traction? why?


Answer

Dc series Motor is used in traction because it require high
starting torque at initial condition

Is This Answer Correct ?    14 Yes 3 No

Question { Bhel, 14994 }

What is the acessaries distribution transformer ?


Answer

1.Tank with Radiator
2.Conservator with top cover
3.core
4.core channel and base channel
5.cotton tape and webbing tape
6.lv and hv coils
7.runner and dove tail runner
8.earth foil
9.MPC wire
8.kraft paper
9.transformer oil
10.press board
11.tie rod
12.clamping rod
13.muts and bolts

Is This Answer Correct ?    1 Yes 8 No

Question { 5533 }

define regulation


Answer

The change in secondary voltage from no load to full load
to the no load voltage is called regulation


= Vnl-Vfl/Vnl X 100

Is This Answer Correct ?    12 Yes 1 No