ATTN DIY electricians
Discussion
Found this the other day... it's the type of wiring fault you'll hear refereed to as a widowmaker by sparks.
Below is a generic switch fused spur unit feeding a shaverlight and an extractor off a ring. If you can't figure out the fault and the dangerous implications, you should reconsider whether you should be fiddling with electrics!
Below is a generic switch fused spur unit feeding a shaverlight and an extractor off a ring. If you can't figure out the fault and the dangerous implications, you should reconsider whether you should be fiddling with electrics!
Correct, in so far as the technicality of the fault- neutral switched as normal in a spur but all the lives stuffed in the L out terminal.
The second part though- the reason this is such a nasty little
- is that with the spur switched off only the neutral is disconnected, the circuit is broken and the light/fan will appear dead, ie they won't function, and a voltage indicator L-N at the items will show no voltage.
There will be 230v at all live and neutral terminals though.
(An inductive tester or testing L-E will show voltage)
Take care out there!
The second part though- the reason this is such a nasty little
- is that with the spur switched off only the neutral is disconnected, the circuit is broken and the light/fan will appear dead, ie they won't function, and a voltage indicator L-N at the items will show no voltage. There will be 230v at all live and neutral terminals though.
(An inductive tester or testing L-E will show voltage)
Take care out there!
hairyben said:
There will be 230v at all live and neutral terminals though.
As a committed amateur I always use a mains tester screwdriver - I know such things are scorned but presumably that would flag up it was live? NB: Cousin's husband lost a friend some years ago due to some bodged wiring and a local handyman was killed last year cutting through a water pipe which suddenly went live.
Despite all the supposed horror stories, fixed wiring (even when bodged) has never been a significant safety issue - there is usually another more critical factor buried in the detail - like a husband drilling in a screw without checking for buried wires in the much publicised case of the MP's dead daughter supposedly killed by her installer's botched kitchen electrics - as used to lobby for Part P. The irony is that Part P has forced electrician prices up, so more people are tempted to DIY. It's appliances that cause 95% (or whatever) of all fires/deaths - what are they going to do about that?
When I purchased my first property I kept getting a odd 'buzz' off some items, so I thought I would investigate further.
I found out to my horror that ALL the sockets in the kitchen had NO earth. What someone had done was install an earth wire and just poke it down into the channel but it went nowhere.
Worse case of DIY I have seen was a chap with an extension light out to his shed but had used a combination of bell wire and TV coax.
After shouting at him he said "well, its all wire innit!"
I found out to my horror that ALL the sockets in the kitchen had NO earth. What someone had done was install an earth wire and just poke it down into the channel but it went nowhere.
Worse case of DIY I have seen was a chap with an extension light out to his shed but had used a combination of bell wire and TV coax.
After shouting at him he said "well, its all wire innit!"
Morningside said:
When I purchased my first property I kept getting a odd 'buzz' off some items, so I thought I would investigate further.
I found out to my horror that ALL the sockets in the kitchen had NO earth. What someone had done was install an earth wire and just poke it down into the channel but it went nowhere.
Ahh, had a kitchen fed via a fuse box with no main earth- chrome sockets set into steel splashbacks/worktops meaning any fault would leave the entire workspace live...I found out to my horror that ALL the sockets in the kitchen had NO earth. What someone had done was install an earth wire and just poke it down into the channel but it went nowhere.
Morningside said:
Worse case of DIY I have seen was a chap with an extension light out to his shed but had used a combination of bell wire and TV coax.
After shouting at him he said "well, its all wire innit!"
Pop into any house refurb and see what passes for an extension lead with our eastern cousins... why pay 49p for a plug when you can just stuff bare flex into a socket with another power tools plug? Generally on a p***sh builder refurb I'll return to change at least 2 or 3 of the new sockets I've fitted that have burnt out due to this, or forcing europlugs into BS sockets, etc etc. Some people are dumb enough to let them lose on the fixed wiring itself instead of using a proper sparksAfter shouting at him he said "well, its all wire innit!"
Simpo Two said:
As a committed amateur I always use a mains tester screwdriver - I know such things are scorned but presumably that would flag up it was live?
Shouldn't say this out loud but I'm personally fond of my inductive stick, the kind that self-tests and chirp/flash every few secs. Hold that sounds a bit wrong...Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff