On Thu, 3 Sep 2009 03:47:21 -0700 (PDT), DLB
wrote:

Not additive? Now I am back to the beginning of understanding. Isn't
the motor running at 15amps on either 120v or 240v?

No.

With 120, 15 amps are running through the motor. 15 amps are coming in
one wire and 15 amps are going out through the other.

With 240, 7.5 amps are running through the motor. 7.5 amps coming in
through one wire and 7.5 amps going out through the other.

Two wires in each case. You could almost think of it like a
waterwheel, one wire pouring in the juice, one wire draining it out,
and the juice spinning the motor as it goes through.

OK, OK, I said "almost". It's just an analogy. (;-)

Tom Veatch
Wichita, KS
USA