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Muthuvel
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11kV Voltage Line

10/12/2012 7:43 AM

Is it enough to give only 11KV insulation level for 11kv voltage line?
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PWSlack
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#1

Re: 11kV voltage line

10/12/2012 7:46 AM

Would one give less?

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Muthuvel
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#2
In reply to #1

Re: 11kV voltage line

10/12/2012 7:49 AM

should be higher..
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PWSlack
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#3
In reply to #2

Re: 11kV voltage line

10/12/2012 7:50 AM

Go for it, then.

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Tornado
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#4

Re: 11kV Voltage Line

10/12/2012 10:05 AM

Peak voltage = RMS voltage × √2.

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7anoter4
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#5

Re: 11kV Voltage Line

10/12/2012 1:56 PM
11 kV rated cable it is a cable manufactured according to BS6622.
According to this standard the nominal insulation thickness is 3.4 mm
This insulation thickness is indicated by IEC 60502-2 Table 6 - Nominal thickness of cross-linked polyethylene (XLPE) insulation
for 6/10(12 max.) kV rated voltage cable.
In ch.4.1 of this standard it is stated:
"The rated voltage of the cable for a given application shall be suitable for the operating
conditions in the system in which the cable is used".
To facilitate the selection of the cable,
systems are divided into three categories:
- category A: operated for a short time with one phase earthed[less than 1 min.]
- category B: operated for a short time with one phase earthed[less than 1 hr.]
category C: this category comprises all systems which do not fall into category A or B.[that means more than 1hr]
Table 1 recommends for A and B 6 kV insulation [3.4 mm] and for C 8.7[/15] kV [4.5 mm]
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7anoter4
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#6

Re: 11kV Voltage Line

10/12/2012 6:20 PM
According to IEC 60038 IEC STANDARD VOLTAGES
The highest value of voltage for 11 kV cable it is 12 kV [rms].
The highest value of voltage which occurs under normal operating conditions at any time and
at any point on the system.
It excludes voltage transients, such as those due to system switching, and temporary voltage
variations.
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7anoter4
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#7

Re: 11kV Voltage Line

10/13/2012 1:52 AM

So the answer is: you may use this cable if the normal phase-to-phase voltage[rms] will be not more than 12 KV, in any case, and if the System will work with no phase grounded for more than 1 hr.

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electricalexpert65
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#8

Re: 11kV Voltage Line

10/21/2012 9:22 AM

A system's insulation level is designated by its:

i) Highest System Voltage (for 11kV, this is 12kV)

ii) Power Frequency Withstand Voltage (for 11kV, this is 28kV)

iii) Lightning Inpulse Withstand Voltage (for 11kV, this is 75kV)

Combined, the Insultaion Level of a 11kV system would be: 12/28/75kV
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7anoter4 (3); electricalexpert65 (1); Muthuvel (1); PWSlack (2); Tornado (1)

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