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jaydebruyne

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Apr 6, 2014
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Can you test voltage on a single wire using a multimeter?

If so, how?

I know this sounds like a dumb question but, say I want to find out the common wire on a cylinder stat. Do I just put one probe on the single wire?

(I don't have anything I can test here at home...)
 
You need to connect the multimeter between the wire under test and a known neutral or earth.
 
But, if the circuit is protected by an RCD then if you go live to earth it will trip the RCD?
 
But, if the circuit is protected by an RCD then if you go live to earth it will trip the RCD?

I think thats if multimeter is set to ohms? Voltage shouldn't trip it. Someone else can probably confirm if i'm wrong.
 
you can touch to pipework as that is usually earth but dont set the meter to amps and touch live and cylinder unless you want a probe sized hole in the cylinder and a shorter probe on the meter
 
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The multi meter is testing the voltage difference between the probes.

you can get some voltage indicators that will tell you if voltage is present with a single probe/ single phase test. If you Think of thos screwdriver testers where you would put your thumb on the end to make the neon glow.

Something like the fluke t150 for example, I have one that cost me about 40 squids that does it.
 
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or Di-log combivolt tester. A light on one of the ( joined together) probes comes on when you touch the / a live wire. Nothing with a thumb over the end.
 
Touch it with your tongue

Masood,

Everyone knows this is not correct procedure, as there's a risk other cables could touch your face. The correct way is to lick two fingers ( thumb and first finger work best ) and gently dab cable, if it tingles it's live!!
 
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There is always an earth somewhere, try the screws on a nearby socket.
Neon testers can be deceptive, lighting up as low as 50v
 
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