why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33

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why nearly all the voltage levels are in the multiples of 11
like 3.3 ,6.6 ,33 ,11 kv.....

Question Posted / himanshu chawla

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why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / nisarg d. patel

In India we provide an offset of 10% overload on the rated voltage level to easily accomodate the varying overload.So in accordance with this, 10 KV becomes 11, 60 KV as 66 and so on and so forth.But this convention is not followed in EHV above 500 KV where we follow the international transmission voltage levels like 730 KV, 1200 KV and so on.And also because the form factor is 1.11 so it becomes symmetric to have the transmission level as 1.1, 3.3 etc.

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6 Yes

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why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / kolhe g j

Transformer changes the voltage level. Form factor for
sinusoidal AC 1.1 .

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9 Yes

5 No

why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / brijesh

Because of form factor that is 1.1

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5 Yes

3 No

why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / virendra joshi

correct is just because of form factor ,

Form factor = Rms value / Average value

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4 Yes

2 No

why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / ashi

its due to form factor

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3 Yes

2 No

why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / k.sahadevan nair

In India and other commonwealth countries, in the initial stage maximum generation voltage was 11 KV considering maximum available insulation rating. In order to step up this voltage,secondary of transformers should be 33 KV, 66 KV, 110 KV ,132 KV, 220 KV etc. So HT voltage of all step up/down transformers were fixed at multiples of 11. This has become a practice. This has nothing to do with form factor 1.11
When generation voltage is improved due to advancement of technology it has become difficult to change rating of all existing transformers. Naturally rating of transmission voltage of multiples of 11 continued and still going on. This is not applicable to EHT as this is a recent development and limited to certain countries only.

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1 Yes

0 No

why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / e.subash chandrasekar

Because of form factor 1.1

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1 Yes

1 No

why nearly all the voltage levels are in the multiples of 11 like 3.3 ,6.6 ,33 ,11 kv.......

Answer / er. akil

at 11 kv level losses should be minimum
so.....