Detecting wires

StarX_2

Hi all,

I bought a wire detector as I was about to drill some holes in a wall and didn't want to fry up
This:
http://www.argos.co.uk/webapp/wcs/stores/servlet/Search?storeId=10001&catalogId=3801&langId=-1&searchTerms=7018019&go.x=0&go.y=0

However the light indicating live wire stays always on! The accompanying booklet specifies:
"Static Electricity charges that can develop on drywall and other surfaces will spread the voltage detection area many inches to each side of the actual electrical wire. To aid in locating the wire position, scan holding the unit ½ inch away from the wall surface or place other hand on surface approximately 12 inches from sensor"

Needless to say I try all the above, but the detection is still confusing, to the point it makes no real difference compared to just guessing, as I used to do before buying the tool...

What are you guys using to avoid drilling into live wires/water pipes and other goodies?

Thanks,
StarX

paul_h

These detectors are not 100% accurate.

It's a good start to avoid areas directly in line with electrical fittings, both horizontally and vertically - whilst there is no guarantee, it is considered bad practice to route cables outside these areas... same applies where pipework emerges from walls.

Having solid block walls, I don't seem to have the problem you have, but have seen it on studwork walls. Sweeping the detector back and forth whilst increasing the distance away from the wall will usually give you an idea if there's something there, but it's can be difficult to pinpont the actual position...

squirrelz

I've got a cheap detector from Maplin Electronics and its absolutely useless, anyone know if the £30-50 ones you see are any better?
(I mean the £30-50 detectors, not the ones that are combined with laser levels, teasmades or whatever).

paul_h

As far as I know, they all work on the same principle - like a small metal detector. The live cable detection is done by looking for the 50Hz field around the cable being picked up by the receive coil in the unit.

Unfortunately, as the OP says, these fields spread in studwork walls, and metal framed stud walls are the worst...