Your house is probably wired with one phase going to half the house and the
other phase goiing to the other half. It would be easier to wire it that way
but as you found out half the house can go dark.
The electricity coming into a US house is almost always two hot wires whose
voltages alternate between plus and minus exactly out of phase. Since one
will be positive while the other is negative the "peak" voltage between them
is 220-230 volts (each changes polarity and of course amplitude). The
voltage from either wire to ground will only be 110-115 volts "peak".
If the electricity consumed by your house is balanced there will be no
current flowing on the neutral wire. Seldom would there be a very good
balance. There will almost always be significant curent flowing on the
neutral wire. A ground wire should not have any current flowing on it.
If the wire providing one phase gets broken, then you shouldn't have 220v
anywhere and about half your house would not have electricity.
If the ground is wet where the "break" occured you may still have current
flowing through a short distance of wet dirt/dirty water between the broken
ends. The voltage at your house would be reduced. I suppose there is also a
slight chance the conductor was partially shorted out to ground and the wire
was not broken. That should trip a breaker on the power line before it gets
to your house.
Adding a little more for Chuck to think about. Brass colored screws are
normally hot, silver colored screws are normally neutral. Only ground should
be connected to green. White wires or wires with a ridge or distinguishing
mark are normally neutral but NOT always. A black or red wire is almost
always hot. Three way light switches sometimes use the white side of Romex
to carry the hot side. Most electronics uses black for ground so if an
engineer/technician touches your wiring without reading the code, you stand
a better than 50/50 chance of being electrocuted.
-jeff
----Original Message Follows----
From: hiwayman@xxxxxxx (Walt Wayman)
The guys from the power company who responded didn't seem the least bit
puzzled by this. They hooked up some device near our meter that provided a
temporary cure, said they'd be back the next day to fix it, which they did
by digging down to the interrupted line and repairing it. Although my
curiosity got the better of me and I asked why we had different levels of
electricity in various parts of the house, it evidently was too complicated
to be explained to a moron who they correctly perceived didn't know his amp
from his ohm.
Walt
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