Working on radial circuit, with breaker tripped - safe?

[Con Cunningham]

Hi, I am rewiring my house, or a large part of it at any rate. If I turn off the MCB for a radial circuit, is there any chance I can get a shock from the neutral? (I know that there are no other connections to the radial circuit, but also that the MCB only isolates the live.)

Also, I stupidly bought 2 X 100m reels of 2.5twin / earth cable in local RS store. Its the wrong colour for Ireland - Red and Black cores. If any of you good folk ever visit Dublin it's going for a song, or a pint or two. ;-)

Cheers, Con

[BigWallop]

[The Natural Philosopher]

Ah. What color do they use then? Green green, and green for the earth??

[ARWadsworth]

Green. To be sure.

Adam

[Gnube]

I think you'll find on closer inspection, that'd be green with a green stripe; to be sure to be sure.

Take Care, Gnube {too thick for linux}

[Con Cunningham]

Well, I asked for that :-) Would you care to elaborate under what circumstances this might occur?

Con

[BigWallop]

Because, if other appliances are running on other circuits, they create a lower resistance path to neutral, which then causes the neutral to have a higher potential than earth. So, in which case, if you touch yourself across neutral and earth, then the higher potential in the neutral will flow through you to reach earth, and you will say OUCH ! and drop whatever tool you have in your hand, onto your foot. Then you'll have three points of pain on your body, one where the electricity entered, one where the electricity exited and a sore foot.

:-)) LOL

Hope this explains it a bit better.

[Gnube]

He might even have a chair attached to his ankle, and wear a faint smell of coffee! ;O)

Take Care, Gnube {too thick for linux}

[fred]

In article , BigWallop writes

A differing opinion:

Yes, if the installation is wired incorrectly.

No, if it is wired correctly. In the circumstances BW describes the max diff between any earth & any neutral anywhere in the house at any combination of min/max load should be less than 5V, not really much of a belt.

In my own house I will happily work with just the MCB off, after checking L, N & E with a meter, but would hesitate in a strange house.

As I think someone else advised, touching N to E on your 'turned off' (not isolated :) circuit will trip the RCD (if you have one) in the consumer unit.

[N. Thornton]

Green. To be sure.

Its only on the mainland we have red and black electrons. You cant put your green electrons down red n black wire, obviously. They'd refuse to flow on grounds of taste.

Regards, NT

[Gnube]

;O)

Take Care, Gnube {too thick for linux}

[BigWallop]

ROFL !!!

Now I have heard it all........Colour prejudiced electrons. What ever next ?

:-))

[The Natural Philosopher]

Colored quarks?

[RichardS]

Don't you beleive it. It's all just Spin.....

-- Richard Sampson

email me at richard at olifant d-ot co do-t uk

[stefek.zaba]

Gravity-sensitive ones. On a network-wiring training course attended by a distant colleague, the "instructor" seriously claimed that propagation speed in twisted-pair cable was faster vertically than horizontally.

(It was a bizarre misunderstanding based on a grain of truth, as it turned out: network-premises types use "vertical" to mean "backbone", and "horizontal" to mean "final run out to individual desktop" - think multi-storey buildings and it makes sense. And since you might use fibre or gigabit links in the backbone, but plain old 10BaseT out to individual network ports, the instructor had construced an alternative universe in which the physical orientation of cable made a difference to the speed of signal propagation. An extreme case of "a little knowledge"...)

Stefek