Re: LDI (Re: Tran-Siberian Orchestra Pyro)

On Thu, 22 Nov 2007 09:36:30 -0000, Tomi Holger Engdahl  =

<then@[EMAIL PROTECTED]
> wrote:

> Christian Marg <christian.marg@[EMAIL PROTECTED]
> writes:
>
>> Omni.Tech wrote:
>> > On Nov 20, 9:42 am, Christian Marg <christian.m...@[EMAIL PROTECTED]
>=

>> > wrote:
>> [...]
>>
>> >> Use a bipolar meter (rated for that usage) to detect voltage...
>> >
>> > Not a Unipolar?
>>
>> Hmm - not sure about the Term: I am thinking about one you connect to=

>> two different conductors to check if there is a voltage between them:=

>>
>> Look at http://images.google.com/images?q=3Dduspol
for an Image of wh=
at I
>> mean...
>>
>> In Germany we have "Phasenpruefer" (don't know an english word for it=

>> yet): A Screwdriver with a neon bulb in it. You put your Thumb on its=

>> end and its blade to a conductor: If the Bulb glows, there is some
>> Voltage on the conductor.
>>
>> But: Our electric code demands a "bipolar" voltage check, because the=

>> "Phasenpruefer" also glows if you put the blade to a wire with an ope=
n
>> end running parallel to one with voltage...
>
> There is always other case where "Phasenpruefer" can fail.
> The "Phasenpruefer" can fail in case you are very well insulated
> away from ground sources. In that case there is not enough
> "leakage" through you that the would make the neon bulb to flow.
>
> So the electrical code in Finland as well demands using a
> "bipolar" voltage check to make sure that there are no
> electricity on the wire before starting working with it.
>
> There are different types of voltage tester that work quite similarly
> to screwdriver with nenon bulb on it:
> http://www.maplin.co.uk/Module.aspx?ModuleNo=3D10294&doy=3D22m11&C=3DS=
O&U=3Dstrat15
> http://www.maplin.co.uk/Module.aspx?ModuleNo=3D30584&doy=3D22m11&C=3DS=
O&U=3Dstrat15
> http://www.maplin.co.uk/Module.aspx?ModuleNo=3D45560&doy=3D22m11&C=3DS=
O&U=3Dstrat15
> http://www.maplin.co.uk/Module.aspx?ModuleNo=3D12840&doy=3D22m11&C=3DS=
O&U=3Dstrat15
>
>


Or the most common failure whereby the tester dies & stops registering  =

voltage. Hence in the UK one is supposed to test the tester before & aft=
er  =

use with a proving box. I've never seen one of these but I have va****ise=
d  =

the tip of a screwdriver after the neon tester identified one circuit as=
  =

live & another as dead. & then when I rechecked it turned out to have di=
ed.