More and more major electric companies are going to 125 VAC +/- 2-volts as the
standard with voltages on the "+" side being common during the warmer months
when the load, due to air conditioning, is greater. In fact, the vast majority
of major electric companies in this country now are running this standard.
In this area, Dallas, Texas, area, the ambient line voltage has been 125 VAC
+/- 2-volts since at least the mid 1970s. TXU, now Energy Futures Holding
Company, the company by which I was employed, as a telecommunications
consultant, for over 10-years, is the electric company for this part of Texas.
In fact, the electric company for almost half the State of Texas.
During my tenure with TXU, I was on the "Speakers' Bureau" which provided
presentations, on all sorts of topics, to clubs, and other organizations.
Although my usual topics were lightning protection and grounding, at every
presentation someone would ask why their light bulbs did not last that long.
The reason for this is that most light bulbs sold, at all sorts of locations,
were rated for 120-volts and, with the higher voltage supplied, were basically
overloaded. The solution was to purchase bulbs rated at 130-volts.
These 130-volt bulbs are available at most home improvement centers, as well as
lighting specialty stores. But, even at home improvement stores, they are not
that easy to find. Frankly, since the 120-volt bulbs did not last that long,
people would have to come back and purchase more bulbs which, in turn, provided
more profit to the establishment.
The higher voltages are run because more kilowatt-hours can be provided without
having to update the distribution lines. The cost of updating these lines, to
reduce IR losses, would be prohibitive. As such, higher voltages! Glen, K9STH
Website: http://k9sth.net
From: "Joe Subich, W4TV" <lists@subich.com>
To: amps@contesting.com
Sent: Saturday, January 24, 2015 11:07 AM
Subject: Re: [Amps] Vendor For Transformer Rewind
> Is there anywhere in the US that still has 120/240 volt power?
Most residential in the US is 120/240 - even 123/246 as utilities
push the limits to minimize transmission losses.
Just for fun, I just checked my line voltage. Here in a semi-rural
area on Saturday morning with no particularly heavy load conditions
(neither heat nor A/C), I'm seeing 122.5/245 V. If I were rewinding,
I would consider 208/220/230/245 and maybe 260 (or 208/220/235/250)
as I expect the overvoltage to continue to worsen.
The increasing number of devices with switching supplies will not
be impacted by 20% overvoltage, but tubes, etc. don't like even 10%
overvoltage if you're looking to get maximum filament life.
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