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nhadkine
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Join Date: Apr 2011
Posts: 21

Current Through Neutral

08/08/2011 10:16 AM

there is 200kva three phase distribution transformer with dy11 vector group star connected secondary...lighting load is connected to its star connected secondary..when current at its phases measured at peak load its found r phase current 185amp;y phase 145amp;b phase 131amp then please tell me how much current should flow through neutral practicaly as well theroticaly..with formula..how to calculate current through neutral..
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PWSlack
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#1

Re: current through neutral

08/08/2011 10:17 AM

It's the vector sum of the three currents in the original posting. Kirchoff's Law applies.

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TonyS
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#2

Re: Current Through Neutral

08/08/2011 10:48 AM

To our OP, when you do you own homework you get more knowledge from it.

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hbadhan
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Location: India
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#3

Re: Current Through Neutral

08/08/2011 12:15 PM

Current through neutral - practically: Use tong tester.

Current through neutral - theoretically : Use Kirchoff's law (Vector summation !!!)

Pl. share the difference you notice in the two values.
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soebfatehi
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#4
In reply to #3

Re: Current Through Neutral

08/08/2011 11:28 PM

"Pl. share the difference you notice in the two values." - hbadhan

. . . and then we will able to write all about metering technologies and limitations of measuring with tong testers . . . .

btw: is your vector group really dy11? or is it Dyn11?
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nhadkine
Active Contributor

Join Date: Apr 2011
Posts: 21
#6
In reply to #4

Re: Current Through Neutral

08/09/2011 12:37 AM

Dyn11
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hbadhan
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#7
In reply to #4

Re: Current Through Neutral

08/10/2011 10:38 AM

Soebfatehi - My previous posting was not intended the way you (mis)understood and reacted so strangely.

Nhadkine - Neutral current is 48.54 A. Hope by now you know how.
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nhadkine
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#8
In reply to #7

Re: Current Through Neutral

08/10/2011 10:59 AM

no not at all..
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nhadkine
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Posts: 21
#9
In reply to #7

Re: Current Through Neutral

08/12/2011 10:24 PM

i understood sir how u calculate the neutral current 48.54amp when line currents are 185;145;131amp..but sir above current i measured by tongtester as well i measured neutral current by tongtester that shows only 1.22amp so will you please tell me whats wrong with transformer...
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soebfatehi
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#10
In reply to #9

Re: Current Through Neutral

08/12/2011 11:03 PM

nhadkine - - - please see my earlier post (#4) . . . .
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nhadkine
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Posts: 21
#11
In reply to #4

Re: Current Through Neutral

08/13/2011 12:24 AM

i measured neutral current by tongtester its 0.06amp...and the vector group is Dyn11..but sir when the load is unbalanced there should be more current through neutral..yeaturday i measured folowing current Rph 158:Yph 165;Bph 142amp and neutral curent is 0.06amp..so please guide..
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soebfatehi
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#12
In reply to #11

Re: Current Through Neutral

08/13/2011 12:35 AM

please share the calculation method you followed to get a much higher value . . .
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soebfatehi
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#5

Re: Current Through Neutral

08/08/2011 11:32 PM

http://www.powerlogic.com/literature/3000HO0824_PSEngSolutions.pdf will also help you to "understand" neutral currents . . .
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Users who posted comments:

hbadhan (2); nhadkine (4); PWSlack (1); soebfatehi (4); TonyS (1)

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