In article ,
LRod wrote:
On Thu, 17 Mar 2005 02:28:59 GMT, "David Merrill"
wrote:

And there we have it, after only 63 posts and counting!

May I be allowed an attempt to summarize:

- possibly improved life of jointer motor
(this one still hasn't been clarified to my satisfaction)

I don't remember that being claimed, but I can dispense with it
quickly (I thought I already had in my original response). From the
standpoint of the motor windings, it's always running on 120V. Either
the windings are wired in parallel (120V supply) or the windings are
wired in series (240V). Since the motor windings are always seeing
120V it can't possibly have any different life expectancy based on the
input voltage.

Well, things aren't quite that simple. grin

"All else being equal" -- things like distance from the main breaker
panel, gauge of the distribution wire, etc. -- and which I must note
are usually _not_ equal ;

The 240v powered motor tends not to 'bog down' as much / as fast as the
120V powered one. This is attributable to the lower 'line losses' upstream
of the motor, resulting in what is effectively a "stiffer" power supply.

"Amps drawn" goes up as the load goes up, with the supply voltage remaining
constant.

*IF* the supply voltage does _not_ remain constant, but 'sags', the amps
drawn goes up even *more*, to compensate for the 'sag'.

A result of 'all of the above", plus some other things: voltage sag is
more pronounced and longer duration at 120V than 240V.

Such "parasitic' losses in the motor go up as the *square* of the current.

This _can_ have an adverse affect on motor longevity.

This is what I understand based on all these posts. Guys, if I'm still
missing or mis-stating something, take your best shot :-)

I think you have probably summarized it accurately with the above
noted exception.

--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net