It's all about the center tapped grounded conductor.

Secondary side:

120V----Neutral----120V
^-------240V-------^

Grounded in the center.

And on the primary side:

^-------4160V-------^
|
Grounded on one side.

Make sense?

Or:

Take two flashlight batteries with taps on each end and between the two.

Opposite ends gives 3.0VDC, but any end to the center gives 1.5VDC.

Now spin the batteries at 3600 RPM!

[Linked Image]

[This message has been edited by sparky66wv (edited 11-01-2004).]

-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI