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Join Date: Oct 2009
Posts: 20

The Earthing Resistance

03/04/2017 3:28 AM

What is the standard or recommended earthing for each rod resistance for power house containing HV generators and step down transformers ?

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#1

Re: The earthing rersistance

03/04/2017 6:34 AM

In my opinion, you don't need to calculate earthing for each rod resistance. What do you need is the maximum touch and step voltage. You may follow IEEE 665/1995 ch. 5.2 Ground grid design and IEEE 80/2013 ch.14. Evaluation of ground resistance or BS 7430 ch.7.2 Earthed generating sets and ch.9 Earth electrode systems.

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#2

Re: The earthing rersistance

03/04/2017 10:52 AM

As 7of4 said, you don’t need individual rod resistance, what you do need is the total earth nest resistance. To do this fall of potential tests are required which takes in to account step voltage.

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Commentator

Join Date: Feb 2015
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#3

Re: The Earthing Rersistance

03/05/2017 3:51 AM

Started to answer, but read the question wrong-- I thought you meant EarthLING resistance.

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#4

Re: The Earthing Resistance

03/05/2017 6:13 PM

Resistance is futile. We are the bored.

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Commentator

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#5
In reply to #4

Re: The Earthing Resistance

03/05/2017 6:22 PM

Seven of nine of my colleagues would agree.

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Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

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#6

Re: The Earthing Resistance

03/06/2017 11:58 AM

Whatever it is, it needs to operate the appropriate circuit protective device(s) in the event of a fault.

If in doubt, consult a local qualified Electrical Engineer, who will assess the (proposed) installation and advise on the basis of local standards.

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