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# NETA IV TEST

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## NETA IV TEST

I took the NETA IV exam this Monday. There was maybe one or two questions from this entire site on the exam!!!

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Originally Posted by MartyCoyne
I took the NETA IV exam this Monday. There was maybe one or two questions from this entire site on the exam!!!
How did it go? Do you have any info to share?

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Originally Posted by ejbrewer
How did it go? Do you have any info to share?
I don't remember a lot of questions but I will post as they come back to me!!

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Originally Posted by MartyCoyne
I don't remember a lot of questions but I will post as they come back to me!!
1000kva 34.5kv to 480v secondary transformer 5% imp. apply 480v to primary side and short secondary to ground. What is primary fault current?

Last edited by MartyCoyne; 5 Days Ago at 06:20 AM.

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Originally Posted by MartyCoyne
1000kva 34.5kv to 480v secondary transformer 5% imp. apply 480v to primary side and ground secondary. What is primary fault current?
8.1A?

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Originally Posted by Lestracy31
8.1A?
1000000/34500*1.732=16.73a
34500*.05=1725v
480 is to 1725 as X is to 16.73
480/1725=.2782 .2782*16.73=4.65a pri

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Originally Posted by MartyCoyne
1000000/34500*1.732=16.73a
34500*.05=1725v
480 is to 1725 as X is to 16.73
480/1725=.2782 .2782*16.73=4.65a pri

thx forgot sqrt3 in my Ibase calculation

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Originally Posted by MartyCoyne
1000kva 34.5kv to 480v secondary transformer 5% imp. apply 480v to primary side and ground secondary. What is primary fault current?
Assuming D-Y

Turns Ratio 34.5k to 277 = 124.5:1
Sec. phase voltage at 480 primary = 3.86V
Line Voltage from 480 primary = 6.68V
1,000,000VA / (1.732*6.7V) = 86.4kA
Secondary SC Current = 86.4/.05 = 1,729kA
Primary Current = 1,729,000 / 124.5 = 13.88kA SC