On Tue, 04 Sep 2007 20:00:07 -0400, Ned Simmons
wrote:

On Tue, 04 Sep 2007 18:48:18 -0400, clare at snyder.on.ca wrote:

On Tue, 04 Sep 2007 16:08:17 -0500, Ignoramus15584
wrote:

On Tue, 4 Sep 2007 13:40:14 -0700, 42etus wrote:

OTOH, there's just something wrong about
putting a 25 amp cable on a 50 amp breaker running
to a 38 amp load.


Actually you do this kind of thing every time you plug a table lamp wired
with 18 gauge wire into a wall outlet protected by a 20 amp breaker.

That is not a very good analogy.

i

Sure isn't, because the 1 amp table lamp is on a 7 amp cord in a 15
amp circuit.

Seems like a perfectly good analogy to me. The cord is sized
considering the nature of the load, not the capacity of the circuit
that's feeding it. The welder in question draws about 30A @ 30% duty
cycle.


However, when running a welder on an extention cord, you want a cord
capable of handling AT LEAST 120% of the expected load to reduce
voltage drop.

Unlike induction motors, most welders are tolerant of low input
voltage. The 185T will operate on 208V circuits, so if it's being
supplied by a typical 240V feed there'd have to be an awfully big drop
to bother it.


My little "MIG" welder runs on a 15 amp circuit on 110 volts. On a 50
foot 16 guage cord at full output the voltage drops to about 96 volts.
That reduces the maximum current of an already borderline welder
significantly.(14% voltage drop roughly 28% power drop?????)

--
Posted via a free Usenet account from http://www.teranews.com