Don't think this is a stupid question ...
Out of curiousity (I have no plans to ever try this) - if I was using a cordless drill (plastic outer case), and was drilling into the wall....and accidentally drilled into a live wire carrying 240V - what would happen??????????
The drill bit would be the only metal part exposed ...... would it just spark and probably snap in two ?? worse than this?
Again, I have no intention of doing this - just wondering, Andrew
Since wires are ran in close pairs, the chances are the bit would tangle in such a way that both wires would be at least nicked, causing a short and blowing the breaker. The spark could ignite flammable materials in the wall, I suppose.
Nothing would happen to you because, as you note, you are insulated. If you were using a corded drill, it probably wouldn't make any difference since most are rated as "double insulated", but if I'm wrong on what that means, the current would just find an additional path to ground and still blow the circuit breaker.
At any rate, a metal path from wire to person could potentially electrify you. This is only a problem if you're touching a ground (concrete and bare feet, or unusually conductive soled shoes, etc.), since electricity doesn't do anything to you if it doesn't have a place to go.
Tim
-- Deep Fryer: a very philosophical monk. Website:
"andrew_h" think this is a stupid question ...
** The drill bit would cut the wire and break the circuit - be a real pain having to replace that length of wire hidden inside a wall.The worst case scenario is when the person with the drill in their hands is standing on a wet floor or ground with wet shoes or bare feet. Also, when the person is in the habit of guiding the drill by placing their fingers around the drill chuck while it is spinning. They could then certainly receive a serious or even fatal shock.
Another serious hazard is where the person with the drill is using a metal ladder - receiving a shock while up a high ladder may trigger them falling and being badly injured that way.
........ Phil
When put a screw into a cable, which was not where it should have been, there was just a loud pop and the fuse blew.
R >Thanks for all your replies - great stuff...
Going back to the drill - the cordless ones (I use anyway) are all plastic, even the chuck part. Therefore, would that mean there is NO chance of a shock travelling to my hand and then through my body to ground ??? Plastic would not conduct, so basically the tool is double insulated - no chance of a shock?
I was actually drilling a hole yesterday ... cordless drill batteries were all flat. So I had to use a power drill - its half metal (handle bit is plastic, but chuck and bit behind is metal) and isnt grounded. It would have been VERY unlikely there were cables behind ... but after drilling one hole I stopped and thought 'dont be a fool'. Might have been overkill, but I turned the power to that circuit off and then did it.
Most US building codes require that unarmored wiring (romex and such) be a couple of inches behind the wall surface, or have a protective metal plate. The provisions are often ignored.
If you get a little RatShack amplifier/speaker box and a telephone pickup coil, you can track the wires inside the wall pretty well.
John
John,
Tell me more about this Ratshack speaker box and telephone coil idea????
That sounds very interesting ... so it'll pick up roughly where wires are in the wall?
Better than those 'voltage' detectors......that detects nothing in the walls?
John Lark> >
You could use a pocket AM radio as well.
Regarding a telephone pickup coil, the power wiring induces a signal into the coil. The signal is amplified causing the speaker to buzz when the coil is near a power wire.
A 'fox and hound' is a commercial product that could be used for this purpose.
Yup.
He might also select his tools so that he only drills what needs drilling.
Those looks really good (drill-stops) ... are hardly used here in Australia, as far as I've seen.
I'll get some!
ah, you mean some one is drilling holes (hammer drill) for para bolts into barred conduit ? :))
-- Real Programmers Do things like this. http://webpages.charter.net/jamie_5
Not a stupid question at all. I see alarm company installers run a long
6 ft. bit UP a wall into the attic above where power lines might be stapled to the studs.This really spooks me as I see so many power lines over a stud that I have to push out of the way while drilling DOWN the wall.
When I have to blindly drill where there just might be a power line, I use both a newer model of stud finder with a live power detector. Those little power line detector wands don't seem to be as sensitive. Then I also use a circuit finder that you plug a transmitter into a live outlet and use the probe to listen for a tone.
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