Hi, I've come across this strange setup on a set of flats I'm doing work on and wondered what people think.
There are 4 flats on the 1st and 2nd floor (ground floor is a shop) with their own supply from the street. The supply enters the building from underground at the bottom of the stairs, a DNO cable supplying a 3x100a cutout, but there is also a 25mm earth coming from under the street to the MET. There is a PME sticker, then the supply goes to a big old switch. (first pic)
Then there is a 4 core SWA to a cupboard upstairs with the distribution boards in it, which feeds another 3x100a cutout. In that cutout the earth and neutral terminals are linked, and then tails as normal to the meters. (second pic)
It seems like tn-s to the first cutout then tn-c-s to the second cutout, but I don't think the SWA sheath or big switch are earthed.
There are 4 flats on the 1st and 2nd floor (ground floor is a shop) with their own supply from the street. The supply enters the building from underground at the bottom of the stairs, a DNO cable supplying a 3x100a cutout, but there is also a 25mm earth coming from under the street to the MET. There is a PME sticker, then the supply goes to a big old switch. (first pic)
Then there is a 4 core SWA to a cupboard upstairs with the distribution boards in it, which feeds another 3x100a cutout. In that cutout the earth and neutral terminals are linked, and then tails as normal to the meters. (second pic)
It seems like tn-s to the first cutout then tn-c-s to the second cutout, but I don't think the SWA sheath or big switch are earthed.
![[ElectriciansForums.net] Earthing to 1st floor flats](https://electricians.s3.eu-west-1.amazonaws.com/data/attachments/40/40689-9d7193b476dcba66424af88c98db1b5c.jpg)
![[ElectriciansForums.net] Earthing to 1st floor flats](https://electricians.s3.eu-west-1.amazonaws.com/data/attachments/40/40690-fae95bfbdfd1a29e607c032255b25d8c.jpg)
