Electrocution case

[Bill]

In message , Steve Firth writes

Last year I helped a friend replace her kitchen cupboards. When we took down one of them there was a neatly drilled hole in the plaster behind it with no rawl plug in it but with some very nice and quite artistic black scorch lines radiating from it for about 1/2" all around and a pencilled note saying "do not use"! It must have been interesting to observe! It was also directly above a 13A twin outlet that was still in use, after digging a hole in the plaster it was clear that the live had been neatly cut. The circuit had been used for years with a break in the live side. Oh and there were only wired fuses in a very overloaded and similarly blackened CU which has now been replaced with a new split load one.

Darwin must love DIYers.

[Steve Firth]

Yes, thanks for that. I experienced something similar years (decades) ago. But that was when rodents had chewed through a cable and had managed the implausible combination of severing the earth, exposing the conductor on the line and then connecting the severed earth to the line. This left the casing of the cooker live.

The report is at least a plausible explanation of how it could have been OK on installation but lethal later. Also interesting that the new regs will do nothing to avert this situation and that those responsible were all "professionals".

[Dave Plowman (News)]

Hmm. Have you evidence this was caused by DIY? Most wouldn't rest after such an incident and get it fixed. Not so many so called pros - especially kitchen fitters who seem to be on piece rate. It's not their problem after they leave - especially if things still 'work'.

[Ian Stirling]

Last screw, with it sitting on the bit of the screwdriver held in aforementioned insulared drill?

[Richard Porter]

Now read the rest of my post.

[Richard Porter]

Or plastic wall plug, screw a bit too long, only touches the wire on the last turn or two by which time you're only holding the insulated handle of the screwdriver. Still, you'd think the installer would give the rack a bit of a tug just to make sure it was firmly fixed.

[Dave Plowman (News)]

Heh heh. But didn't it say it was movement of the screw which had frayed through the insulation?.

Of course, anyone with sense would have moved the rack a half inch so the screw touched the neutral...

[Ian Middleton]

This thing of the cable not going vertical to the socket/appliance caught me out once. I was fitting shelves in the my kitcen about 18 inches to the left of the cooker switch/single socket. I too made the assumption that the cable would run down vertical after having removed the switch cover to verify the cable went straight up. Nope I drilled through the 32A (?) cooker feed blowing both the consumer unit fuse and electricity board 60A fuse !!!! (oh and ruining my nice new 6mm drill bit).

After power was restored later that evening (didn't get charged as wrong rated fuse had been fitted, so not my fault (?)) cut holes in plaster board to reveal a nice loop of cable curving gracefully behind the plaster board down to the switch. Why it didn't just go straight down, rather than go straight past the vertical then curve back to the switch I will never know, probably because someone couldn't be bothered to pull the excess cable out.

[Dave Plowman (News)]

You must have been using some force to drill plasterboard if you manage to drill through a loose cable behind it?

[N. Thornton]

From all I've read here it looks to me like an accident that no sensible regulation or practice change could be expected to avoid. Why do I say that? Nothing is 100% safe, not one thing in this world. Our job is to use the limietd resources we've got to reduce risks as much as poss, that means reducing the bigger ones. To put any measure in place that would have prevented this would cost so much that many more lives would be lost in other areas where oney was not spent on risk reduction. It would not be cost effective, more lives would be lost than saved. Same as with bathroom equipotential bonding, same problem. Whoever came up with that one does not seems to grasp this.

At some time we have to bite the bullet of reality: we can not make the world totally safe. It cant be done. And trying to will make us all poorer, and lses resources to implement improvements will result in more deaths not less.

The one realistic thing that would have made the difference was if the family had enough brain cells between them to realise that if they were getting shocks off the rack that it was a danger and should have been removed, with power off. If they cant look after themselves on such an obvious and basic level... not much we can do to help them. Very sad, but unfortunately theres no way to wish deaths away, and no way to stop a moron finding ways to endanger themselves.

NT

[Ian Middleton]

Nope, drill (new masonary bit I think) just cut through the plaster board and straight square onto the cable bang (a loud bang in fact) inbetween the live and neutral, cutting the central earth wire. I think the cable was held nicely in place (for me to drill through it) by large amounts of dot and daub plaster as well.

[Paul Mc Cann]

Did that twice, many years ago using a metal bodied B&D drill with a hedge cutter attachment.

First time clean cut, no shock, nothing.

Second time the cable snagged and I found it difficult to let go the machine as it give me a shock every time the blade touched the live wire. I eventually managed to throw it to the ground.

I was wearing wellies so that may have helped

[Capitol]

Two immediate examples similar to this come to mind. A friend installed a picture hook on a drylined wall in the toilet and the tip of the pin (

[raden]

In message , IMM writes

No, she has Corgis

go and read

and learn some correct English

[Bill]

In message , "Dave Plowman (News)" writes

Hi Dave, a very good point. Thinking about it I was probably a bit biased having seen some of the definite DIY that had been done there. As you say more likely a "Pro". My apologies.

[Dave Plowman (News)]

Right. If it had been loose, I'd have thought the bit would have pushed it out of the way.

FWIW, I always use an HSS drill for plasterboard. Don't think you need a masonry one. And little pressure at a slow speed. Never quite sure what lurks behind. ;-)

[Dave Plowman (News)]

Right. Of course it could be either. But it's a bit like gas work. Most DIYers, I'd say, would not touch gas if they didn't think they were capable. After all, they're the ones who will suffer. Cowboys don't care who suffers - unless it's them.

Heh heh. You never need to apologise on here for expressing an opinion or making a valid comment. If you did, you'd double the bandwidth...

[Andy Dingley]

There's a Metabo with built-in voltage sensing that shuts the drill off if it finds a buried live cable.

[Andy Dingley]

Protection isn't meant to protect (that's an unrealistic expectation)

- it's meant to warn you that you've hit it.

[Paul Mc Cann]

Prefer a lip and spur myself.