In uk.transport.london message
, Fri, 16 Apr 2010 01:34:32, Q posted:

"Dr J R Stockton" wrote in message
. invalid...

Now join the three
neutrals into one; the three return currents, being of different phases,
add to nothing, with balanced loads; therefore the neutral, carrying
only off-balance currents, can be comparatively thin. See sig.

Or not... Subject to the type of load it is recommended that you up-rate the
neutral's

Capacitive loads, those with a poor crest factor and high THD will
(unchecked) burn your neutral bars/links out in no time at all.

Symmetrical linear loads, such as pure capacitative or inductive,
maintain the balance of neutral currents, by symmetry.

Third (and its multiples) harmonic distortion currents will add in the
neutral rather than cancelling. But it takes a lot of THD to give the
same current in the neutral as is in each of the lives.

In the quoted part, "comparatively" is a comparison between the joined
neutral and the three unjoined ones; and "thin" really means cross-
section rather than diameter.

--
(c) John Stockton, near London.
Web URL:http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, & links.
Correct = 4-line sig. separator as above, a line precisely "-- " (RFC5536/7)
Do not Mail News to me. Before a reply, quote with "" or " " (RFC5536/7)