On Sat, 7 Jan 2017 11:33:15 -0600, Leon lcb11211@swbelldotnet wrote:

On 1/7/2017 10:21 AM, John McCoy wrote:
Leon lcb11211@swbelldotnet wrote in news:Q9idnQchSrQoje3FnZ2dnUU7-
:

On 1/6/2017 3:40 PM, John McCoy wrote:

It's a variety of historical reasons. 110V is what Edison
originally used for his first DC systems (for reasons no
longer understood, that was considered "safe").

Probably considered safe because DC lost voltage quickly the farther
from the generator the lines went. IIRC there had to be a generator
within a few miles of the consumer. AC on the other hand still had
quite a bight many miles away.

AC doesn't have the same losses as DC because it can be
transferred at a higher voltage. If you sent AC from the
generating station to your house at 120V you'd have the
same losses as with DC. The wires on the utility pole
outside your house are 4600V (or something in that range,
different utilities use various distribution voltages).

FWIW I was speaking about the time when electricity was just starting to
be used in homes. DC was not practical as there had to be way too many
generation stations. Only the affluent were served in the early days,
they could afford to have/pay for a DC generation station near by.

The wires out side my home on utility poles are maybe 480 volt NOT forty
six thousand. Now the voltage on the hi power transmission lines are
much much higher but they are not near by and they go to transformer
stations where the voltage is dropped and sent to consumers and still
more power pole transformers.. The closest transformer station to me is
8 miles away.

More like eleven thousand (maybe twenty-two thousand).


Today "safe" is considered to be around 12V. I can't think
of any situation where you'd consider 110V to be "safe",
unless you're comparing it to something like 1200V.

John