Question About Fault Current

[kiwiNCFC]

Hello!

I'm an apprentice and today I was working on a new build. It's a TT supply and I have a question. Sorry if it's a stupid one.

I was taking a Ze reading at the DB and I got 900 ohms . This was obviously wrong so I went outside to go check the earth stake.

I went outside and the bolt that holds the clamp to the rod had sheared off thus meaning the earthing conductor was not connected to the rod. I then put a new crimp on and re-bolted it to the rod, back inside I tested for Ze again and got a good 29 ohms . 

Back when I was about to put the new clamp on, I asked my boss if I could turn off the supply. He said no and to just put a new one on. Now obviously if you touch the MET/Bonded pipes/Earth Rod in an electrically safe system, you will not get a shock. But let's say for example someone had a chop saw plugged into the sockets and on that chop saw there was a L-E fault would I get a shock now because I'm touching the earth and the fault is following the Earth fault loop path?

Hope someone can clear this up!

Thanks

 

[kiwiNCFC]

I've had a look at a few. If the above scenario happened on a TN system, am I right in thinking I would get a shock as the Earth and Neutral are connected together at either the supply or distributor? Thus meaning I am forming part of a circuit?

 

[NozSpark]

That would depend on if there was an alternative, much better route. However with most services now coming in in hep pipe you can't guarantee that is the case.

Personally I wouldn't disconnect or connect an earthing conductor with the power on.. I wouldn't leave it disconnected with the power on either.