2395 Earth Electrode Resistance Testing

[Hogshaw]

Earth Electrode Resistance Testing 2395

Hey guys, I'm up for my 2395 soon, although I understand how each of the three methods is carried out I can not seem to find anywhere that tells me why one method would be used over another?

some of my sample paper answers are till use test method one (temporary spikes) and other answers are to use the earth fault loop impedance tester test method 3? If anyone can help me with this would be greatly appreciated.

Thanks in advance

 

[trev]

https://www.google.co.uk/url?sa=t&r...9j3BGHp9CbhaSPtbg&sig2=yhcZFXmOExEDWPV2ylUW4w

https://www.google.co.uk/url?sa=t&r...9uduAO3tdwLQXHFkQ&sig2=i6nsluIw5f1lOGIYWP3TRw

A couple of things there that might come in handy for you.

 

[Simonslimline]

We had a question in one of our UPK units on the 2357 regarding this... It was dependent on whether a supply was already present or not if i remember correctly.

 

[Richard Burns]

When you measure the Ra of a rod using an earth electrode tester this is a more precise measurement and is used when measuring accurately the resistance of the earth rod where this is required for generators and such like.

When you measure the Ra using an EFLI tester than the resistance measured includes the resistance of the line conductor, however in comparison to the overall resistance of the rod when installing a TT installation this resistance is negligible as the value is not required to be precise so this method is appropriate.

Stakeless testing is way of measuring the Ra without disconnection of the earth but can be affected by the methods of earthing in use so should be used with caution but it can give an accurate value. Mostly used for situations where the earth cannot be disconnected easily and so allows monitoring of the earth resistance over time without disruption.

Not totally clued up on this so do check with Tev's links.

 

[IQ Electrical]

We had a question in one of our UPK units on the 2357 regarding this... It was dependent on whether a supply was already present or not if i remember correctly.

Correct!