Hi
Are these things worth having
If they say a cable isn't live - is that always 100% risk your life on it true?
(guesses)
If it showed live, then I switched a circuit off, and it showed "off" with the thing put in the same place, I'd probably trust that.
I'll await more experienced comments though...
cheers, clive
If they say there are no volts there usually are not - the problem is that they detect volts - not power - so often say the circuit is live because of trivial leakage when it isn't so you start to disbelieve them. The result is well documented and predates electric power - go read the story of Brer Rabbit and the thorn bush or the little boy who cried wolf.
"I'm sure it isn't really live" - eeekk...
For low impedance circuits you really need a low impedance test set. A couple of 15W bulbs in parallel and a pair of leads is often much more reliable than a box full of electronics.
non-contact though, and better than licking your finger and brushing it along a row of terminals :-)
I'd rather go for something like the Fluke T50 Tester - also has continuity, indication of polarity, covers AC and DC +12V, -12V, 24V,
50V, 120V, 230V, 400V, 690V which means you can use it for cars, trucks, telephones (50V), sngle and 3-phase electrics.Slightly more expensive, much more versatile - replaces a multimeter for most electrical work, and more robust.
No. Regardless of the type of tester you must always follow an approved testing procedure - basically, test the tester against a known live to make sure it works, test the suspect conductor, then test the tester against a known live to make sure it *still* works.
Have a look at
Owain
Reliable?...most of the time! certainly NOT 100%. They are very difficult to see in sunlight, a better version made by VoltStick also emits a sound [other makes available but we use VoltSticks] A decent one will even tell you which side of a Twin & CPC cable is the live through the outer covering. Handy for tracing breaks in flexes and cables. Will not work through SWA or any metallic sheath [obvious really]. Also available is MagStick which senses a magnetic field, handy for checking solenoid valves. Whichever you decide on DONT trust your life to it, they are handy for a quick check only. Work on the premise that 'even when you are sure it is dead treat it like it is still live!' Always 'prove' it before and after a test.
HTH
|Hi | |Are these things worth having |
When I was a apprentice Electricians Mate the rule was "Put the fuses in your pocket" Otherwise use a multimeter.
I'd second that. Worth it for "tracing the break in flex" alone.
Wouldn't trust my life to it.
Thomas Prufer
Mind you, that isn't always foolproof - I've worked on three phase where someone had managed to wire it up so that the fuses were bypassed. Fortunately, I was using an insulating floor mat and following the other rule of never touching anything except the terminals you are working on. It was only later, when I was following an odd cable that I discovered I had spent an hour or so working on live equipment.
Colin Bignell
You can risk your own life on it Dave ;-)
As others have said they have their uses. I have one that has a slider control for sensitivity and a buzzer as well as an LED. Unfortunately I can't remember where I got it - possibly TLC or CPC. I use it to tell if a particular cable is live without having to get at the conductors in it. It's not foolproof: a completely disconnected cable running parallel to a live one will pick up enough induced energy to operate the tester.
I use a neon screwdriver to tell me if I really shouldn't touch a particular cable or terminal (and a quick flick of a dry finger, standing in dry rubber-soled shoes on a dry floor before grabbing hold of it!) Actually I sometimes have to lick my finger before putting it to the end of the neon tester to get it to light up since there's usually too little conductivity when everything's really dry.
A neon tester can light from the current through high-value resistors in things like motorised valves in central heating controls. To properly test these I use a 2-probe tester with a couple of LEDs (wired presumably through a big resistor in the handle of the probe) which will definitely only light up if there's really a fairly serious circuit energised. (You also get only one LED lighting up if it's rectified AC such as across the motor of a spring-return zone valve in the holding position - e.g.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.