simple tester to avoid me electrocuting myself

[Thermo]

Im after a simple tester that will tell me if a wire is live or not. Quite often in our work when we are landscaping we come across a cable thats buried in the garden. Despite assurances from the householder im always sceptical. Im after something thats robust, cheap and doesnt need to be plugged in.

Am i right in thinking i need a voltage detector?

 

[Softus]

It's a tricky one Thermo, because unless you can get at the bare conductor (e.g. at one end of the cable) then you can never really be sure.

One of these would help relieve some anxiety though (but it's only for AC):

 

[Taylortwocities]

And may not work if the armour of an SWA cable is earthed.

 

[Thermo]

Half the stuff we come across isnt amoured anyway! Its the diy type stuff thats been done years ago and the clients are sure its safe......yeah right.

Thanks for your help chaps much appreciated

 

[Shocker]

A clamp meter will do.
All you do is put the clamp meter around the cable(/put the cable through the clamp meter) and the clamp meter will measure the voltage and if there is any current flowing.

It only measures AC. Any cables will probably be carrying mains voltage AC. If its any DC it will probably be low voltage which will just tingle your fingers/

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[Taylortwocities]

I'm not sure about the kewtech one but be careful, a lot of clamp meters only work when they are round a single conductor (eg phase) not the whole cable.

 

[RF Lighting]

I do have a clamp meter which will do multicore cables, but the majority will not.

The one in the picture certainly will not. That is for single cores only.

 

[plugwash]

If it is an armoured cable then it is going to be very hard to tell for sure if it is live or not. Voltage detectors are poor at the best of times and armour is effectively a form of screening.

If you are at all unsure treat the cable as if it were live until you have cut it and checked it directly.

 

[DESL]

If you are at all unsure treat the cable as if it were live until you have cut it and checked it directly.

What with an insulated spade!!!

 

[Thermo]

most of the stuff we come across is not armoured, its usually bodge jobs from days gone by that have been buried under old patios etc.

by the way i use a sparky for putting all the new stuff in!

thanks gents

 

[Adam_151]

What with an insulated spade!!!

You may well laugh, but the idea is similar what happens on underground cable jointing to prove a cable is dead...

http://www.spiketool.com/SPIKEhome.html

(but no, don't spade the cable )

 

[kevnurse]

I suggest that if the cable is armoured that Thermo and his spade are protected; otherwise whats the point of the armour !?

Thermo, get yourself a 230V voltage detector with a pointed end that you place against a suspect cable while pressing your thumb on a button on the detector. Something like the one that was pictured by Softus (I think the green thing is the button). They are very handy. I had one and then lost it, sadly.

 

[Jim2287]

handy but very unreliable ... sometimes they show voltage when the cable is dead, sometimes they dont show voltage when the cable is live

 

[bernardgreen]

Clamp meters will not show any current when clamped round live and neutral as the outward current in live will cancel the equal and opposite current returning in the neutral. the result is there is no magnetic field for the clamp to detect.

Clamped round just one wire they will show nothing if there is no current flowing. There can be 230 volts on the wire but if there is no current flowing the clamp meter will not have anything to indicate.

The only safe option is to treat any buried cable as live. If it is an "unknown" cable in that it serves no known purpose and/or its supply point is unknown then it really should be investigated and made safe.

 

[cheesepuff]

try this:
http://www.mkelectric.co.uk/products/item.asp?itemid=3863&rangeid=1002

its called the powertracer and it detects 240v to 415v. Mr RF has one

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