Extraneous bonds values

Pete999 · Dec 21, 2014

Leckie said:
The 0.05 figure is just the value that is acceptable for a connection. So if you fit an earth clamp to a copper pipe, the value between the conductor connected to the clamp terminal and the pipe it's connected to should be no more than 0.05ohms. It's to confirm the connection is good. If you had a 70m run of 10sq.mm, it's not going to measure 0.05 ohms end to end is it.

https://www.youtube.com/watch?v=rnvNfI__kYU

There is a thought/recommendation that if you earth conductor is more than 25meters in length the you could up the csa from 20mm to 16mm (see link)

Geoffsd · Dec 21, 2014

It's strange that he doesn't say why.

Also, the extraneous-c-p is the pipe which comes out of the ground, not where it is bonded, but that's another story.

Pete999 · Dec 21, 2014

Geoffsd said:
It's strange that he doesn't say why.

Also, the extraneous-c-p is the pipe which comes out of the ground, not where it is bonded, but that's another story.

He is testing from the pipe as opposed to the clamp to prove he has a decent connection, your 1st point imo he is saying that increasing the csa of the cable will reduce the resistance, don't think there is anything written down, I believe its just a recomendation