little advice please

[1983]

Hi all after some advise please. A shop with a basment and flats on top has a tns 2phase and neutral supply one for shop one for flat. doing ze test am I right thinking that if I disconnect the main earth wouldn't that put the occupier of the flat in danger?

 

[telectrix]

can you diss. the main earth just from the shop CU, leaving it connected to the flat? alternatively, you could isolate the flat CU.

 

[uksparks]

Yes it most certainly would, you need to arrange a suitable time to do it convenient with both. You only need to disconnect it from that installation and ensure bonding to gas and water etc are disconnected to avoid parallel paths.

 

[davesparks]

If you disconnect the earthing conductor with the installation live then yes you are putting your life at risk along with the lives of any users of the installation.

 

[1983]

Thank you for your feed backs appreciated. It's for my niceic assessment if he was to ask for me to do a ze test. Davessparks I was going to safely isolate my side but realised about the flat on top seen as they share the same earth back to the tranny

 

[7029 dave]

isolate the whole lot, before dropping out the earth conductor.

 

[davesparks]

Davessparks I was going to safely isolate my side but realised about the flat on top seen as they share the same earth back to the tranny

Before disconnecting the earthing conductor you must isolate the installation at the main switch so that the whole installation is dead. Failure to do so places your life in danger, the leakage current flowing through it may be tiny, but don't forget it could take as little as 0.05A to kill you.
You cannot measure Ze without having disconnected all cpcs and bonding in the installation from the suppliers earthing connection.
This basic concept must have been covered at some point during your apprenticeship surely?

 

[uksparks]

It's good to see the OP has queried it, it shows the right thoughts are going through his head.

 

[trev]

If he can't figure a simple thing like this out it makes me question
A His ability
B Is he ready to proudly wear the NIC badge of competence
C Why the hell they'd let him (Although I know the answer to that one = £ )

 

[Geordie Spark]

If he can't figure a simple thing like this out it makes me question
A His ability
B Is he ready to proudly wear the NIC badge of competence
C Why the hell they'd let him (Although I know the answer to that one = £ )

Is that little worky ticket messin aboot wi' yer siggy son??

Get yersel away doon an introduce 'im t' the Geordie kiss!!

 

[trev]

Is that little worky ticket messin aboot wi' yer siggy son??

Get yersel away doon an introduce 'im t' the Geordie kiss!!

I think I've made my point for now Fatha.

 

[Geordie Spark]

I think I've made my point for now Fatha.

Good lad.