Anyone ever had a L to N fault in a brand new socket

[AJB Temple]

I have just spent about 6 hours in a freezing cold building tracing a continuity fault between L and CPC in a ring final circuit in an outbuilding. Not yet commissioned. This has 8 pairs of Hager SS flush double sockets in it (ie 16 sockets) above a quartz counter, and 4 double sockets beneath the counter in extremely difficult to get to spots (wired before the counter went in. Plus two junction boxes.

For some reason I had a L to CPC continuity fault (ie a short) and tracked this down to the lower section. The whole lot is wired in 6mm for some reason with 2.5mm CPC.

All of the doubles below are metal clad and all are Hager except for one, which is Click. I ended up removing all of the lower sockets and extending the cables (impossible to get a screwdriver in) and lowering the sockets. The fault turned out to be the Click metal clad unit which has an internal connection between L and CPC within the socket construction itself. Megger shows continuity between L and CPC on the socket, with no wires in it at all.

I was astounded. Brand new kit supplied a year ago, never been powered up. No visible damage of any kind. Does this often happen?

 

[Dave OCD]

First time I've heard of that one, most unusual ! And the last thing you'd expect too. Well done for finding it !

 

[freddo]

Had a similar fault in a socket I think. A screw used for fixing the socket together was inside the socket. Must have been dropped in by the assembler! I think it was a floor box socket. Probably posted a photo here somewhere.

 

[mattg4321]

Very unusual to get a faulty click socket!

 

[littlespark]

A “new” socket that’s a year old?

Not commissioned building? Are you sure?
It’s maybe had something high load plugged in for a while.

I had one old socket go faulty on me. Neighbour phoned with tripped rcd. I was there til 10pm trying to find a fault on the wiring.
Had all the sockets off, and every leg was clear.
It’s not something I would have thought of before, but now I check

 

[AJB Temple]

Yes. It is a slightly over a year old. It is a complete new, very large kitchen and utility installation started in May 2019 that was never finished or commissioned because Covid caused huge delays to a building project linking this building with another one. The electrician (very nice guy) who did the first fix work departed to work for someone in Dublin having suffered thefts and gone bust, and the builder doing the building work (complete new building linking two structures) died from Covid. It's a high spec job owned by a German lady who has been in Germany most of the time. It's now back on track.

 

[HappyHippyDad]

As above. Very rare.
It has happened to me once. It completely throws you when you are fault finding as your detective skills and past experiences are all pointing towards other possibilities.

I remember my brain slowly and painfully forcing itself to ignore past experience and just listen to the test results which all lead to a faulty (new) socket. I changed the socket and all was OK.