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Re: Electrical Wire Safety



Quoting Gary Karshner <gkarshner@STMARYTX.EDU>:
Your particular potential is determined by the averag=
e=20
load. If average loads in your neighborhood change so will your line=
=20
potential.

Nope.

The voltage fed to a residence is regulated by ... PHYSICS.

Sometimes for each house, sometimes for a group of four houses
or thereabouts, there is a transformer. It serves *two*
purposes
-- it is a stepdown transformer in the usual sense, and
-- it is a voltage regulator.

It regulates the voltage because it is a *saturable* transformer.
The max flux in the core is determined by the saturation level
in the core material. Think of the classic sigmoid B versus H
diagram.

Since the flux is known and the frequency is known, the voltage
is pretty much determined by the Maxwell equation
voltage = flux dot

Of course the Thevenin impedance of the transformer is not quite
zero, because the shelf on the B versus H diagram is not quite
flat ... but it is pretty darn good.