end terrace house

[oldtimer]

All
I have just changed the CU in my brother inlaws new house he has a 2 bedroom end terrace and there is 4 in the block he has a 3 phase swa cable supply to his house and this supplies all 4 houses in the block so when he gets his extention done next year and then gets the house tested for building control (Scotland) How do you test the main ELI when there is 3 other houses connected to the main cable via 3 16mm earth cable on an earth block. Plus how if one of the other houses were to be tested how would you get around the various other paths to earth ? If you see what I mean.

 

[Des 56]

I think I see what you mean
Is your train of thought that these others would need disconnecting from the MET in order to measure Ze ?
My opinion would be that they are parrellel paths that could exist on the earthing system of any estate except that the actual connection of these properties are in your visible location
When we measure Ze it doesn't exclude these parrallel paths in Tn systems in all other situations
Either inquire off the supplier what they declare as the Ze for that area or take a reading and ignore these other main earths

 

[oldtimer]

thanks for the reply
I could disconnect the other earths to get a "true" reading but what reading would i get if his house was one of the other 3 ie you cannot tap on the door of the other 3 houses to see who has the 3 phase supply and distribution fuses in their house.
Ironically i am in that position as the house 3 doors down has this set up. o hum
Also forgot to ask is this set up common across the country or only in scotland

 

[Sintra]

thanks for the reply
I could disconnect the other earths to get a "true" reading but what reading would i get if his house was one of the other 3 ie you cannot tap on the door of the other 3 houses to see who has the 3 phase supply and distribution fuses in their house.
Ironically i am in that position as the hous 3 doors down has this set up. o hum
Also gorgot to ask is this set up common across the country or only in scotland

I would test Ze in the property that concerns you as it would be totally impractible to isolate everyones supply to test at true origin. Yes you will have parallel paths but no way round it.