In article , Dan C wrote:
On Wed, 11 May 2005 21:17:13 +0000, Doug Miller wrote:

Yes, but it's a lot smaller than18 gauge, and it doesn't have the same color
coding as thermostat wire. The latter isn't too much of a problem, as long as
the OP pays attention to his connections, but the former might be: the

Correct. It's usually 24 AWG.

resistance in cat-5 cable will be considerably higher than in 18ga thermostat
wire.

Wrong. The resistance is exactly the same (near zero ohms). What's
different is the current-handling capability, which is completely
different than resistance.

The first thing to observe, when attempting to correct someone else, is to
make sure that you first have your _own_ facts straight. You unfortunately
omitted to do this.

Far from being "exactly the same", the resistance of a 24ga conductor is more
than _four_times_ that of an 18ga conductor of the same length.

Nor is it "near zero ohms" in either case, except for unusual values of "near"
or "zero".

Finally, it is precisely the resistance of a conductor (along with the
properties of its insulation) that determines its capacity to carry current.

18ga wi 0.00751 ohms/ft = 0.225 ohms in 30 ft (length cited by the OP)
24ga wi 0.0302 ohms/ft = 0.906 ohms in 30 ft

http://www.epanorama.net/documents/w...esistance.html

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?