Re: x10 over three phase

["Harrison, Mark (Alliance)" <Mark.Harrison@xxxxxxx>]

> assuming you survive.

Very unlikely, I'm afraid.

As I understand things, the reason people tend to surive normal 230v AC
shocks is that every 100th of a second, the PD between the bit of their
body connected to the mains drops to zero volts relative to the bit
touching the earth. At these points (or close to them) it's _relatively_
easy to shake free of the "spark radius" and stop the current
flowing
through you.

The problem with touching two different phases of three phase is
two-fold.

Firstly, there is an AC voltage peaking at about 400v between the
phases.

Secondly, it's likely that part of you will also be grounded at the time
- this means that part of your body will always have a voltage of at
least 100ish volts - as one phase gets to zero, the next has take off.

Mark Harrison
European IT Manager, BP/Bovis Alliance
Tel: +44 181 869 1439
Fax: +44 181 423 7711
SMTP: Mark.Harrison@xxxxxxx



-----Original Message-----
From: Nigel Orr [mailto:nigel.orr@xxxxxxx]
Sent: 05 March 1999 09:34
To: ukha_d@xxxxxxx
Subject: [ukha_d] Re: x10 over three phase


At 21:59 04/03/99 -0000, you wrote:
>heating had to be Night Storage Heaters. This pushed the
>total load well above the limit of the existing supply and the
>local electricity board supplied a 3 phase supply.

We had something similar- with a separate "Off-Peak" supply (may
have
been
a N.Ireland peculiarity- a bit like Economy 7, but cheaper!)

>>From a wiring point of view this is nightmare city :-((

Agreed!  And you _don't_ want to get phases crossed- it's something you
only do _once_- assuming you survive, you're a lot more careful next
time...

>No two outlets on different phases were allowed within 2 metres
>of each other as 415V would exist between them.

I believe this restriction no longer applies.

Nigel
--
Nigel Orr                  Research Associate   O   ______
Underwater Acoustics Group,              o / o    \_/(
Dept of Electrical and Electronic Engineering     (_   <   _ (
University of Newcastle Upon Tyne             \______/ \(

------------------------------------------------------------------------
Internet FileZone: Always FREE!
Instantly store & access your valuable PC files on the net,
from any Web browser.
SIGN UP NOW - http://offers.egroups.com/click/235/0

eGroup home: http://www.eGroups.com/list/ukha_d
Free Web-based e-mail groups by eGroups.com


------------------------------------------------------------------------
Internet FileZone: Always FREE!
Instantly store & access your valuable PC files on the net,
from any Web browser.
SIGN UP NOW - http://offers.egroups.com/click/235/0

eGroup home: http://www.eGroups.com/list/ukha_d
Free Web-based e-mail groups by eGroups.com