Have a major problem

[westward10]

You worry too much Vorts

 

[David M]

A bit more speculation, the sparky may not have tested the IR @500v looking at the cable I suspect the outside light has a PIR sensor and even though he could have tested L,SL&N - E he may have been worried about damaging it.
Without the full details & circumstances its difficult to make an accurate conclusion.

 

[telectrix]

maybe if he'd used the old (proper) colours, R,Y,B, the OP might have seen the cable and been able to avoid nailing it.so I blame IET ( IEE as was).

 

[KEV 1 N]

RCDs are there to prevent serious injury or death.
They don't stop electric shocks.
It's very unlikely the person involved would have died, the RCD would have tripped had the fault current have been high enough.

With my kitchen mishap, the lighting rcbo didn't trip, this may be because it was only 100v, and the shock was more of a tingle

 

[Dave Jenkins]

Since there was an RCD in circuit (new CU) why did the electrician fit metal capping? If I understand correctly, capping is principally to protect against plastering trowel damage. In the past, I've earthed metal capping, but have only used plastic in recent years...
If he'd used plastic I guess the fault wouldn't have presented??

 

[Dave OCD]

Since there was an RCD in circuit (new CU) why did the electrician fit metal capping? If I understand correctly, capping is principally to protect against plastering trowel damage. In the past, I've earthed metal capping, but have only used plastic in recent years...
If he'd used plastic I guess the fault wouldn't have presented??

Possibly not but it might depending on the conductivity of the damp wall.

 

[Richard Burns]

Because the RCD did not trip the fault current would have been <30mA, noticeable but not deadly (in most cases). That is the resistance to earth was greater than 80kΩ.
It is possible that IR testing would not pick up this fault as the fault would not be internal to the cable and may not connect back to the earth bar, the fault is direct to true earth via the damp wall.
If the cable was tested without connection to the the earth bar then no fault would be seen as there is no connection from line to the cpc.
If the cable was tested when the cpc was connected to the earth bar then the fault may have been noted but may not depending on the resistance of the wall to the earth bar.

 

[Guitarist]

Metal capping should be banned in my opinion. PVC oval conduit fixed with screws and penny washers.

 

[telectrix]

Metal capping should be banned in my opinion. PVC oval conduit fixed with screws and penny washers.

why not use the correct clips?
Tower Oval Conduit Clips 16mm White Pack of 5 - https://www.screwfix.com/p/tower-oval-conduit-clips-16mm-white-pack-of-5/72359

 

[Sparkingmad]

I have read this thread a number of times now and I have to agree that this is a culmination of several events that have led up to the customer getting a shock. Putting aside whether you were right or wrong for nailing back the capping or should have called the electrician back to do it. The cable got nicked, the wall was plastered, the installation was 2nd fixed and new board fitted, testing was carried out and no fault was detected. I think it plausible that this fault could go undetected unless the exact same circumstances where recreated ie when carrying out Insulation Resistance testing someone would have to be touching the damp wall and making an earth path. The electrician obviously ---- a brick when you informed him of what had happened and went on the major defensive. Fault or failing of the world we live in these days of the blame culture and sue the arse off you inherited from USA. It takes 0.25A to potentially kill someone if it goes across the heart if my understanding and memory is correct. That is why we as an industry use 30mA rcd’s which are supposed to operate at 0.03A flowing from Live to Earth fault current. Now the only concern I would have is if the RCD/RCBO did in fact not trip! I know my old tester used to have a round metal button on the front of it which u could use to measure touch voltage which had to be less than 50V also to ensure that magic figure or 0.25A wasn’t achieved.
RCD or RCBO’s are not designed to prevent you from getting a shock they are there to prevent it from killing you.
Years ago an electrician was taken to court when a father was cutting the lawn and severed the flex, as he went in to pull the plug his child grabbed the lead and touched the live conductor and got a shock,the rcd hadnt tripped when cable had got cut. However once the child had completed the path to earth the rcd tripped as it was supposed to. The customers were under the impression that the rcd was supposed to prevent electricution or in this case electric shocks from taking place. His child survived unhurt, the case was eventually thrown out as the protective device functioned as it should and the electrician had fulfilled his obligation under the regulations.
My conclusion from all this is the electrician handled himself poorly and immediately went on the defensive which didn’t help resolve the situation and used the wrong terminology towards you and the customers putting the fear of god into you. There is always a right and wrong way to word things and conduct yourself.
Hope you can all work this out and even if you don’t use this guy again lessons can be learnt from both sides.
I personally don’t use metal capping or plastic capping can’t stand the stuff it’s always plastic oval conduit and chase them in the wall even if it’s dry lined.

 

[Toneyz]

Sorry but I can not see how this can be economical it will increase the job cost. Plastic capping instead of metal if the same thing happened the nail will still make the damp wall live.

 

[littlespark]

Devil's advocate:- is it 100% certain it was this nailed cable that caused the shock? Is there other circuits coming down the same wall to sockets for example? Maybe they are nailed also?
If OP works for his family, I hope they back him up and not point the finger solely at him

 

[Guitarist]

why not use the correct clips?
Tower Oval Conduit Clips 16mm White Pack of 5 - https://www.screwfix.com/p/tower-oval-conduit-clips-16mm-white-pack-of-5/72359

I have done, and do on occasions, but I find it's easier to keep the chase as shallow as possible with the washer method.

 

[Deleted member 26818]

Don’t like the clips for oval conduit, take up too much room.

 

[Sparkie30]

Stopped using oval,capping years ago. Chase 30-40mm deep and always carry a bag of bonding.

Never a problem with builder or plasters.

 

[EbolaSideRoom]

he said they would get a 6amp shock and it could kill them because it was over so many milliamps and because it was a floating earth rcb wouldn't operate. i'm starting to get ****ed off with this guy now

I'm not surprised.
Rule #1 of all electrical work - do not allow people to receive electric shocks!!
Regardless of the circumstances if a client of mine or anyone associated with them (or the job) had received an electric shock I'd be mortified, never mind who could be said to be at fault. Pointing the finger elsewhere just reeks of guilt, IMO. I'd look for a second opinion on the job, from someone suitably qualified and somewhat independent from the installer.
Also, and I'm not sure if this question has been answered elsewhere in his thread so please forgive me for asking again, was the errant capping plastic, or metal?

 

[Wilko]

... please forgive me for asking again, was the errant capping plastic, or metal?

My assumption is metal, in that a single nail "made the capping live".

 

[Deleted member 9648]

My assumption is metal, in that a single nail "made the capping live".

That was my assumption as well.
Many issues spring to mind with metal capping, not least that minor damage and a live nail head a couple of mm across will be amplified into a live strip of steel perhaps a couple of metres long. But also it's razor sharp edges may cut through insulation. I've seen this happen when it's installed, but also post install when cables are moved by other trades during building works.
I have used round plastic conduit for many years, only considering plastic capping for budget jobs.

 

[123]

Round plastic conduit is pretty much what everyone uses this side of the pond. Don't think wholesalers even stock capping

 

[telectrix]

only problem with the round conduit is that you need to chase into the brick. oval, on the other hand is generally only plaster depth.