Dubious AC readings

[psaffrey]

I am planning to mount a microwave in my kitchen using these:

tested the wall, which feels like brick, with a cheap AC detector and it beeped all over the wall, right the way over my cooker to the far wall, a width of 8 feet and up as high as I could reach. Not believing this reading, I bought a higher spec reader:

?ts=48938but that still said the wall was a mass of current. I live in a basement flat and this is a central wall. It's on the other side of the flat to my consumer unit and all the kitchen sockets are at skirting level. The light switch is on a different wall and there are no unit lights, although there is a cooker hood to the side of where I intended to mount. The other side of the wall has a single light switch, but I've measured and the wall is a foot thick. Could something be fooling my reader? I didn't think cable would be buried in brick anyway. Of course, I'm very reluctant to drill until I'm sure.

I could just mount on the side wall next to it, which reads no current at all, but this would leave the heaviest part of the microwave the furthest from the shelf mounting - this would leave me worrying that I don't have wall plugs that are heavy duty enough to carry the weight.

Peter

[RW]

> I tested the wall, which feels like brick, with a cheap AC detector

Borrow a digital test meter and try the pos lead in the wall a few mm and the neg lead to a good earth. See if there's any current.

*Might* be a short from a bad cable to earth through dampness etc.

[meow2222]

Theres not much chance of hitting a wire, and if you do it aint hard to fix. Get your money back and dont waste any more time with those things.

NT

[Phil L]

> I tested the wall, which feels like brick, with a cheap AC detector

?ts=48938>> but that still said the wall was a mass of current. I live in a

"but that still said the wall was a mass of current"

It didn't - it said there is metal present - this could be any number of things, plasterboard nails or screws if the wall is boarded, expanded metal if the wall is rendered over any number of problematic surfaces, tie wires within the wall, the list goes on.......

[Dave Plowman (News)]

?ts=48938> but that still said the wall was a mass of current.

That's a metal - not live cable finder.

[Peter Parry]

There is probably a one in a million chance, and as every engineer knows those occur two times out of three.

[dave]

Use rawl *bolts* if you are in any doubt. B&Q sell them.

[1501]

Even possibly foil-backed plasterboard.

[psaffrey]

No, I was using the AC detection setting.

Peter

[psaffrey]

Really? How do I fix a parted live cable through a drill sized hole in a brick wall?

Peter

[Dave Plowman (News)]

Did you check it works correctly over a known live cable location? These things are a bit hit or miss.

[Robert Campbell]

My detector beeped continuously until I touched the wall with my other hand - then it only beeped over known live cable locations - it was a solid structural wall, if that makes any difference.

[psaffrey]

This is what I did. Pressing my hand on the wall next to the detector stopped the beeping. Drilled holes with no problems.

Much, much procrastination, but job finally done. Thanks for your help everyone :)

Peter

[meow2222]

Tough questions... now lemme think... make the hole bigger?

NT