i found this question being asked on a group bulletin board...here is the initial question:

Just a quick question for the electricians amongst you......

Often when I am wiring Low Voltage and High Current circuits, I
will 'double-up' cables. By this I mean that instead of using 1
length of 10mm squared cable, I will use 2 lengths of 6mm squared
cable wired in parallel. By doing this, the cabling is much easier to
work with and is probably a little cheaper. Whilst this method is
fine for my R & D, I am unsure whether this is standard practice or
is acceptable at all.
I have quickly skimmed through some electrical practice books, but I
can't find any reference to it. It might be illegal for all I know.

Please can you advise?
Does anybody else use this method?

here is a reply from another visitor to the same group..
reply #1
Well, I'm not an electrician and I'm not really able to interpret the code
for you but my initial reaction was 'probably not permitted'. I only have a
copy of the 1996 code, which is superseded, but section 310-4 allows
conductors in parallel for general wiring under certain conditions but
meeting ampacity through aggregation as you describe isn't permitted
(although for some reason 620-12a appears to allow this for lighting
circuits). There are other sections that reference conductors in parallel but
these seem to be the salient sections.

There are a lot of books on "practical electrical wiring" but the text by
that title by H. P. Richter is almost a standard and does address this
subject. I'd suggest picking up a copy and a copy of the code for reference.
I'm no expert and while wiring isn't 'rocket science' in most cases, in some
cases its worse - sneaky little electrons and fields...

reply# 2:

Tell this to the Long Island Power Authority for their plans to lay the 1300 mm squared DC power cables across the LI Sound to Connecticut. See: http://www.crosssoundcable.com/NewFiles/hardware.htm .

SOME COMPANY has long been a fan of laying underground power cable. Do it right but do it. It is called "Instant Power Company". Communities wanting renewable energy need only someone to lay cable and be the "battery" for everyone. an organisation should be more attuned to these needs than they seem to be. It is a double burden for everyone to both generate their own energy *and* store it.


i was just wondering if anybody here has any comments on this topic?



[This message has been edited by chick (edited 10-24-2002).]