Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 2

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Why all voltage level are multiples of 11, like 220V, 440V,
1100V instead of 200V, 400V, 1000V?

Question Posted / md shahnawaz

9 Answers
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Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / bikash

since all the voltage generation are in average and we use
rms quantities for computation. so we need to convert the
average to rms simply by multiplying the form factor 1.11.
thats how the voltage levels are in the multiple of 11.

Is This Answer Correct ?

56 Yes

8 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / thunder bird

AC voltages are sinusoidal in propagation. the electrical machines are designed for root mean square(RMS) values of voltage which is nothing but equivalent D.C voltage.whereas insulation, transmission etc are calculated for average(AVG) values which is 1.1 times RMS value.1.1 is form factor for sinusoidal waves. (form factor = RMS value/ AVG value). so a generator may be producing 400 kV RMS but in common mans' term it will be 440kV.

Is This Answer Correct ?

4 Yes

3 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / girish

AC sine wave form factor will be of RMS value / Average value
of a sine wave, that will be 1.11, so all voltage levels are
multiples of 11

Is This Answer Correct ?

4 Yes

4 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / sakthi

its a historical reason. initial days design people assumed that line losses will be around 10%. so they have designed to 110% to get 100%. but nowadays it has been changed. now we are using 400V instead of before 440V. 230V instead of 220V before. There is nothing to do with form factor. its not involving any of the design calculations.

Is This Answer Correct ?

3 Yes

3 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / cheech

just for shits & giggles

Is This Answer Correct ?

2 Yes

2 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / mohamed

We are designed the alternators windings should be wound '11o' clock position.

Is This Answer Correct ?

0 Yes

3 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / sreeknp

when converting average value to r m s multiplication factor
is 1.11 hence voltages

Is This Answer Correct ?

4 Yes

8 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / aks

we don't now. Mr.MD.Shahnawaz pls tell the correct answer.

Is This Answer Correct ?

2 Yes

13 No

Why all voltage level are multiples of 11, like 220V, 440V, 1100V instead of 200V, 400V, 1000V?..

Answer / sundeep

Because anywhere the generator rating is 11kv...so the
voltages are stepped up or stepped down in the multiples of
11...

Is This Answer Correct ?

3 Yes

16 No

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