I’ve been asked to add a couple of extra points to the single ring main in a flat. Building fabric is concrete, all of the electrical installation is steel conduit buried in the concrete.
I opened the consumer unit and could only see one CPC for a radial socket, as well as the main Earth. No other CPC’s visible.
There was no supply head, just the incoming line conductors (looked like 16mm) coming through an opening behind the C.U, no bonding for gas or water. All of the cables disappear down into this opening and I can’t see any other CPC’s or connections down there, plus as it’s all in concrete I can’t get down behind there to look.
I’m guessing the C.U is being fed from a locked cupboard in the communal hallway on that floor, but I couldn’t gain access to it today to check.
I was also hoping that the gas and water would be bonded here or on the incoming to the entire block of flats itself, but again I couldn’t check that today.
The only ring main in the flat (the one I want to add spurs to) has continuity on all conductors, but I couldn’t test the CPC of the ring main at the C.U as there is no visible connection there for the CPC’s, which are present at the socket outlets. I tested at a socket though, and the CPC appears to be continuous as well as being connected to the Earthing - somewhere.
There is no CPC in the lighting circuit either, but the conduit seems to be being used as the CPC. I’ve done a wandering R2 to each light switch and fittings, all have low readings for R2 well within reason.
So my questions are, how do I approach adding the additional sockets in light of what I found, is the steel conduit used as CPC acceptable for the light switches and fittings, and if the gas and water is bonded on the incoming to the block of flats itself / at the communal supplies, is this sufficient?
I opened the consumer unit and could only see one CPC for a radial socket, as well as the main Earth. No other CPC’s visible.
There was no supply head, just the incoming line conductors (looked like 16mm) coming through an opening behind the C.U, no bonding for gas or water. All of the cables disappear down into this opening and I can’t see any other CPC’s or connections down there, plus as it’s all in concrete I can’t get down behind there to look.
I’m guessing the C.U is being fed from a locked cupboard in the communal hallway on that floor, but I couldn’t gain access to it today to check.
I was also hoping that the gas and water would be bonded here or on the incoming to the entire block of flats itself, but again I couldn’t check that today.
The only ring main in the flat (the one I want to add spurs to) has continuity on all conductors, but I couldn’t test the CPC of the ring main at the C.U as there is no visible connection there for the CPC’s, which are present at the socket outlets. I tested at a socket though, and the CPC appears to be continuous as well as being connected to the Earthing - somewhere.
There is no CPC in the lighting circuit either, but the conduit seems to be being used as the CPC. I’ve done a wandering R2 to each light switch and fittings, all have low readings for R2 well within reason.
So my questions are, how do I approach adding the additional sockets in light of what I found, is the steel conduit used as CPC acceptable for the light switches and fittings, and if the gas and water is bonded on the incoming to the block of flats itself / at the communal supplies, is this sufficient?
