Glenn Ashmore wrote:
Wire size is a function of amp load and distance. The #10 leads on the
windlass are only about 2' long so they can carry 50 amps with a voltage
drop of only 2%.

With 50 amps on a 72' run #4 is the absolute minimum size you should use.
Even then including the windlass leads you will be close to 10% voltage
drop. Using #8 you would loose more than 20%.

How are you routing the wire to use up 72' on a 27' boat?


It may be useful to put some reference
points into the analysis.

With a 20% reduction in voltage, a DC
motor would probably see a 20% reduction
in torque, a 20% reduction in rotational
speed, and a 44% reduction in power.

If the expected load is still met with
these reductions, there should be no
problem. The motor will not be damaged
by running at a 20% reduction in
voltage, but the wires may not be too happy.

It is also worth keeping in mind that 50
amperes is only going to be drawn when
the motor is producing its maximum power
output. This should be a relatively
short-duration situation, particularly
since must of us use swells to break an
anchor loose rather than windlasses.

Just stirring the coals.

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----