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Home voltage is 130V?

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Stannon

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Jul 19, 2001, 4:11:36 PM7/19/01
to
I measured my home's voltage. My volt meter shows 130V.
I went to a house nearby but in another city, result 125V.
Measuring voltage in my office, 120V. All with the same
meter. Is my voltage too high? Is it the problem of my
utility company? Can they fix that?

Stannon

-G.

unread,
Jul 20, 2001, 9:31:24 PM7/20/01
to
Yes. I think that's too high. Can you go to your neighbors house and
check the voltage? How confident are you that your meter is accurate?

Stannon wrote:

--
Crows feet are neither crows or feet.
...Discuss....


Thomas Wilk

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Jul 20, 2001, 10:48:08 PM7/20/01
to
Yes, it is a bit high. Call the utility and tell them what you told
the group.

Most likely, its a voltage regulator problem at the substation which
needs to be corrected. Your light bulbs will thank you.

Tom

Stannon <nospam...@yahoo.com> wrote in message
news:f116fa48.01071...@posting.google.com...

Ben Franklin VI

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Jul 20, 2001, 10:54:22 PM7/20/01
to

We don't see this much any more. There was a time when power companies made a
practice of burning off excess generation and supporting undersized
distribution lines by "negative regulation". That is running up the voltage
above the 127 Volt federal limit. Inductive loads used much more power than
their rating. The excess boiled off as heat.

Ask your power company to put a recording voltmeter on your service, likely
they will AND if you have more than 127 the will fix it and promptly LOOSE the
graph.

If you have a high resistance in a neutral it is possible to measure 130 or
more volts on one side of the line and 110 or less on the other side
simultaneously. If the incoming power is above 254 phase A to phase B. Your
transformer needs to be tapped down.

Ben

>rom: nospam...@yahoo.com (Stannon)
>Date: 7/19/01 3:11 PM Central Daylight Time
>Message-id: <f116fa48.01071...@posting.google.com>

db...@sprynet.com

unread,
Jul 20, 2001, 10:58:11 PM7/20/01
to Stannon
call out the utility company and tell them that you cheked your voltage
an itsd 130, and you checked the neighbors, try go get one off another
transformer, about two to three houses away and see if its lower,
probably a bad transformer on the pole, they will want to know about it,
also dont run any delicate instruments like coputers until they fix it.

M6...@webtv.net

unread,
Jul 20, 2001, 11:47:49 PM7/20/01
to
130 volts is okay.Volt readings a little on the high side are
common,where the utility transformer is located close to the house being
served and is lightly loaded.

webm...@diehansonsux.com

unread,
Jul 21, 2001, 12:41:34 AM7/21/01
to
quoting:
>Yes, it is a bit high. Call the utility and tell them what you told
>the group.
>
>Most likely, its a voltage regulator problem at the substation which
>needs to be corrected. Your light bulbs will thank you.


you mention light bulbs.. that reminds me. when I go the the hardware store,
I notice some of the light bulbs are rated at 130v instead of 120v. these
130v bulbs operate at a slightly reduced light output, but last a bit longer
on a normal 120v circuit. I was wondering if these 130v light bulbs are made
for places with abnornally high voltage. of course, the 130v bulbs produce
rated light output and life when operated at 130v.

webm...@diehansonsux.com

unread,
Jul 21, 2001, 1:16:04 AM7/21/01
to
I do know that to at least some devices do not like high circuit voltage.
for example:

1) fluorescent ballasts. many manufacturer's catalogs state that circuit
voltage must stay within cirtain limits, usually + or - 5 volts. catalogs
also state that a ballast rated for 120v operated beond those limits will run
notibly hotter, and will shorten its life. It will also void the warranty.
It may or may not also trip the ballast's internal thermal switch it it gets
hot enough. so a ballast rated at 120v should not be operated at 130v.

2) regular light bulbs. any normal 120v light bulb when operated on a 130v
circuit will experence reduced life, but it will burn slightly brighter.
When we go to the hardware store, look at the different light bulb brands.
some of them will be rated at 130v. this may have something to do with some
people getting stuck with a 130v feed. these 130v bulbs would definatly help
if you have 130v. if you do the oposite; use 130v light bulb on a 120v
circuit, the filiment runs cooler, and the bulb will last somewhat longer,
but it also will give somewhat less light. if you can stand the less light,
then it would be ok to do.

3) sensitve electronics, general. a big no-no! high circuit voltage is one
of the causes of premature failure of many electronic items, usually due to
the overheating it causes. like ballasts and light bulbs, a device rated for
120v should not be operated on 130v. if you live somewhere where you get
stuck with 130v, and can't correct it, then there are special UPS devices for
computers, and also can be used with other electronic equipment. make sure
you buy an UPS that has "voltage regulation", this will keep the voltage from
getting too high. an UPS will also be an excellent surge and spike protecter
too.

In article <f116fa48.01071...@posting.google.com>,
nospam...@yahoo.com says...

Edwin Pawlowski

unread,
Jul 21, 2001, 3:03:55 AM7/21/01
to
"Thomas Wilk" <spong...@worldnet.att.net> wrote in message

> Yes, it is a bit high. Call the utility and tell them what you told
> the group.
>
> Most likely, its a voltage regulator problem at the substation which
> needs to be corrected. Your light bulbs will thank you.
>
> Tom

I had the same thing a few years back. Light bulbs were going fast and I
checked the voltage and found it to be 130. I called the power company and
they said it could not happen, blah, blah blah . . . . . Never happened
again. What a surprise.
Ed
e...@snet.net
http://pages.cthome.net/edhome


Default User

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Jul 21, 2001, 9:29:27 AM7/21/01
to
Sure sounds like a problem to me. Please call the electric
company and suggest that they readjust their extrabulator. The
lady on the phone won't know what that is, but all us linemen
know.

--
Christopher A. Young
We survived Y2K, but will we survive Y2C?
This Y2C is what they are enduring in California: Survivalist
situations caused by the government regulating business and
preventing the free market forces from working.


"Stannon" <nospam...@yahoo.com> wrote in message
news:f116fa48.01071...@posting.google.com...

Calvin Henry-Cotnam

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Jul 21, 2001, 9:53:44 AM7/21/01
to
man...@freewwweb.comSPAM (webm...@diehansonsux.com) said...

>
>you mention light bulbs.. that reminds me. when I go the the hardware store,
>I notice some of the light bulbs are rated at 130v instead of 120v. these
>130v bulbs operate at a slightly reduced light output, but last a bit longer
>on a normal 120v circuit. I was wondering if these 130v light bulbs are made
>for places with abnornally high voltage. of course, the 130v bulbs produce
>rated light output and life when operated at 130v.

I have heard of 130V bulbs as being "rural" light bulbs.

Typically in the past (and probably still!) utility companies would
have longer runs of their power lines on the 120/240 side of the
transformer. Simple economics: a transformer with a certain kVA rating
could supply X number of customers. Since in rural areas the customers
tend to be farther apart, the low voltage side tends to involve longer
runs.

Now, they could order lower rating transformers, but who wants to
maintain a transformer for each customer or two? They could make that
long run with a heavier gauge of wire, but that can be costly too.
So what was often done to ensure that the customer WAAAAY on the far
end of that run got at least 105-110 volts was to use a higher than
normal voltage coming from the transformer, say 130 volts.

Of course, the problem is that the near-end customer finds his light
bulbs going at a much higher rate than his far-end neighbour. I forget
the actual numbers (anyone else know?), but it something like a 5%
increase in voltage reduces the life of a bulb by about 20%.

So, "rural" light bulbs were created for situations like this.

--
Calvin Henry-Cotnam | "Nothing quite livens up a suburban
DAXaCK associates | neighbourhood like a driveway boasting
Richmond Hill, Ontario, Canada | plastic milk crates loaded with crap."
http://home.ica.net/~calvinhc | -- John Oakley, radio talk-show host
-------------------------------------------------------------------------
NOTE: if replying by email, remove the capital letters!

isetta

unread,
Jul 21, 2001, 10:54:23 AM7/21/01
to
In article <IPf67.266914$Z2.32...@nnrp1.uunet.ca>,
NcOaSlP...@ica.net (Calvin Henry-Cotnam) wrote:

> I forget
> the actual numbers (anyone else know?), but it something like a 5%
> increase in voltage reduces the life of a bulb by about 20%.
>


10% increase in voltage decreases the life of a bulb by 50%

--
remove the KNOT to reply via email

Joe

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Jul 21, 2001, 7:28:57 PM7/21/01
to
<< readjust their extrabulator >>

Chris, I thought it was the phidorkle valve or thermothrockle that caused the
problem.

Joe

JBOBST...@AOL.COM

joevan

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Jul 21, 2001, 7:55:35 PM7/21/01
to

Nope, you both got it wrong. It is the thermodiscombobulator.
Can't you guys get anything right. Take a course in spelling for the
first step and then check back with me.
joevan

Default User

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Jul 21, 2001, 9:44:32 PM7/21/01
to
Yes, I'm certain that you are right. But those take a supervisor
lineman to adjust.

Extrabulators, any lineman can adjust those.

You've obviously got some great electrical experence. Most
homeowners would never think to check the phidorkle valve or
thermothrockle.

Great advice!


--
Christopher A. Young
We survived Y2K, but will we survive Y2C?
This Y2C is what they are enduring in California: Survivalist
situations caused by the government regulating business and
preventing the free market forces from working.

"Joe" <jbo...@aol.comnospam> wrote in message
news:20010721192857...@ng-fc1.aol.com...

Mike Burns

unread,
Jul 25, 2001, 6:04:40 PM7/25/01
to
The voltage to your home will vary with time of day, how much current
your neighbors are drawing and other factors. The 130V is a little on
the high side, but not that much of a problem. Low voltage (under 100)
is worse because motors can stall and burn out.

Dan Hicks

unread,
Jul 25, 2001, 7:44:09 PM7/25/01
to

The only real problem might be that light bulbs burn out too fast.
Investing in high voltage (125 or 130V rating) bulbs will solve that,
though you won't have as much of a selection of styles.

The thing you should be sure to do, though, is check multiple (at least
a dozen) outlets throughout your house. If you see more than 3-5 V
variation between outlets then you likely have a bad neutral connection
somewhere. A bad neutral connection can be a real hazard to life and
property.

--
Dan Hicks
Let a fool hold his tongue and he will pass for a sage. --Publilius
Syrus

CBHVAC

unread,
Jul 25, 2001, 8:08:43 PM7/25/01
to
When I was in California, I was convinced, and so were a few others that
Edison varied the rate of voltage....as voltage dropped, amperage went up,
and thats where the power bill comes from. Amazing how the first warm day in
the valley even with all the wind power plants..several thousand...the
voltage dropped at least 4 points and stayed that way till the second cool
week in the fall....


--
www.carolinabreezehvac.com
"Mike Burns" <mike....@honeywell.com> wrote in message
news:3B5F4278...@honeywell.com...

miggedy mike

unread,
Jul 25, 2001, 9:48:53 PM7/25/01
to

"CBHVAC" <in...@carolinabreezehvac.com> wrote in message
news:C9J77.1995$z%.80100@eagle.america.net...

> When I was in California, I was convinced, and so were a few others that
> Edison varied the rate of voltage....as voltage dropped, amperage went up,
> and thats where the power bill comes from. Amazing how the first warm day
in
> the valley even with all the wind power plants..several thousand...the
> voltage dropped at least 4 points and stayed that way till the second cool
> week in the fall....

if theres any proof to that theory, it could lead to a VERY big rebate/class
action lawsuit.


CBHVAC

unread,
Jul 25, 2001, 10:20:48 PM7/25/01
to
Aye...thought that as well..but then, Edison never admitted to the power
head that was wired wrong on a home that we discovered one summers day when
we were soaking wet with sweat, and were attempting to get a unit to
run...got the living daylights knocked out of myself and at the time, the
guy training me...knee on the sand, wet with sweat, and one hand on the top
of the unit....
Same thing if you touched the unit and the fence...lights worked fine
tho..Edison sent a guy out after we called, and requested it, and he
explained that the main wiring leading into the home was wired wrong. Since
I am NOT an electrician by trade, and at the time I was a journeyman, it
made little sense to me....perhaps someone here might fully understand it...


As far as proving that theory....I agree...I thought several times about
getting a recorder from Johnstone supply and letting it run and record the
voltage for a few months...

--
www.carolinabreezehvac.com
"miggedy mike" <mikeinlakew...@hotmail.com> wrote in message
news:9GK77.27063$da.42...@typhoon.we.rr.com...

Jeff Wisnia

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Jul 26, 2001, 12:17:42 AM7/26/01
to
Really? Who told you that stuff about current being "where the power bill comes
from" ?

I'm pretty certain standard household power meter rotors move at a speed
proportional to voltage times current. Can you give me a reference which shows
they respond only to current?

Check the sixth paragraph of this post, the poster sounds like he knows what
he's talking about:

http://isaac.exploratorium.edu/snaktalk/hypermail/0577.html


Jeff

Jeff Wisnia W1BSV Brass Rat '57 ee

"Things which go away by themselves usually come back by themselves."

CBHVAC wrote:

--

CBHVAC

unread,
Jul 26, 2001, 12:40:05 AM7/26/01
to
And what part of volts X Amps did you miss?

That is actually watts BTW...

Tell you what...figure this one out then, IF the AMPERAGE used is NOT what
runs the bill up....

Why is it that a 30 RLA 220VAC motor uses the same amount of voltage, as a
10RLA 220VAC motor, drives the same load, does the same amount of work, but
costs more to run? Both have the same service factor.

Its not rocket science.

Volt: A unit of electrical potential, or pressure.

Ampere (Amp): A unit of measurement for rate of current flow.

Current: The flow of an electrical charge through a conductor with the
ability to overcome resistance and perform work.

Watt: A unit of electrical power, directly converted to work, the product of
voltage and amperage. 746 watts are equal to one HP.

Work: The transfer of energy from one object to another, measured in force
multiplied by distance, or foot pounds.


That pretty much sums it up..its not the voltage that the meter reads, its
the amperage used. 220VAC, is 220VAC, or VDC even, the load, however, is
rated in amps...keep adding things that use power, and the voltage rating
remains the same, (generally), but the amperage draw increases.

I never claimed to be an electrician...but ....its not rocket science.

Amperage use is directly related to a utility bills amount...he said it, and
I did as well, in simpler terms.

"Jeff Wisnia" <jwi...@110.net> wrote in message
news:3B5F99E6...@110.net...

webm...@diehansonsux.com

unread,
Jul 26, 2001, 1:16:10 AM7/26/01
to
quoting:
>The only real problem might be that light bulbs burn out too fast.
>Investing in high voltage (125 or 130V rating) bulbs will solve that,
>though you won't have as much of a selection of styles.


yes light bulbs do burn out fast! in my experience, when I had 130v in my
house, I had a DVD player fried. light bulbs burn out fast, but I did try to
buy as many of the 130v ones as I could. I would have to conclude 130v is
too high. If you have 130v in your house, call the electric company
immediately, and make them reduce your voltage! 130 volts is BAD BAD BAD!

I now know that at least some devices do not like high circuit voltage.
for example:

1) fluorescent ballasts. many manufacturer's catalogs state that circuit
voltage must stay within cirtain limits, usually + or - 5 volts. catalogs
also state that a ballast rated for 120v operated beond those limits will run
notibly hotter, and will shorten its life. It will also void the warranty.
It may or may not also trip the ballast's internal thermal switch it it gets
hot enough. so a ballast rated at 120v should not be operated at 130v.

2) regular light bulbs. any normal 120v light bulb when operated on a 130v

circuit will experence 50% reduced life, but it will burn slightly brighter.

When we go to the hardware store, look at the different light bulb brands.
some of them will be rated at 130v. this may have something to do with some
people getting stuck with a 130v feed. these 130v bulbs would definatly help
if you have 130v. if you do the oposite; use 130v light bulb on a 120v
circuit, the filiment runs cooler, and the bulb will last somewhat longer,
but it also will give somewhat less light. if you can stand the less light,
then it would be ok to do.

3) sensitve electronics, general. a big no-no! high circuit voltage is one
of the causes of premature failure of many electronic items, usually due to
the overheating it causes. like ballasts and light bulbs, a device rated for
120v should not be operated on 130v. if you live somewhere where you get
stuck with 130v, and can't correct it, then there are special UPS devices for
computers, and also can be used with other electronic equipment. make sure
you buy an UPS that has "voltage regulation", this will keep the voltage from
getting too high. an UPS will also be an excellent surge and spike protecter
too.

So any electrical device that is designed to operate on 120 volts should not
be operated on 130 volts!

---------------------------------------------------------------------------


In article <3B5F59C9...@ieee.org>, danh...@ieee.org says...

Chris Lewis

unread,
Jul 26, 2001, 2:16:53 PM7/26/01
to
According to Stannon <nospam...@yahoo.com>:

How good is your meter? Do you really trust it?

Seriously.

Most meters don't do that good a job of measuring AC. So much so,
that some perfectly good meters can read as much as 50V away from what
really is there (eg: peak-reading meters). If you don't understand/know
what the meter is doing with AC, the results can be highly misleading.

I appreciate that you've used the same meter elsewhere, and you do
have voltage measurements that seem more reasonable. So it's
_probably_ telling the truth. But maybe not.
--
Chris Lewis,
For more information on spam, see http://spam.abuse.net/spam

It's not just anyone who gets a Starship Cruiser class named after them.

Chris Lewis

unread,
Jul 26, 2001, 2:21:59 PM7/26/01
to
According to man...@freewwweb.comSPAM <webm...@diehansonsux.com>:

> 3) sensitve electronics, general. a big no-no! high circuit voltage is one
> of the causes of premature failure of many electronic items, usually due to
> the overheating it causes. like ballasts and light bulbs, a device rated for
> 120v should not be operated on 130v. if you live somewhere where you get
> stuck with 130v, and can't correct it, then there are special UPS devices for
> computers, and also can be used with other electronic equipment. make sure
> you buy an UPS that has "voltage regulation", this will keep the voltage from
> getting too high. an UPS will also be an excellent surge and spike protecter
> too.

Generally speaking, "modern" computers (and much else that might be
called "sensitive electronics") don't care that much.

Many are designed to operate with anything from 90V-250V and 50-60Hz,
without the user switching it in any way. This is due to the way
switching power supplies work.

Code says that the power to the house is supposed to be within 5 or 6% of
nominal 240/120V. 130V really isn't that far off. So, if it is _really_
130V, I'd expect relatively little problem except for lightbulbs.

Chris Lewis

unread,
Jul 26, 2001, 3:27:43 PM7/26/01
to
According to CBHVAC <in...@carolinabreezehvac.com>:


> Amperage use is directly related to a utility bills amount...

As long as the voltage stays _fixed_. You can't say that the utility
bill is directly related to amperage. It is directly related to
volts X amps (and power factor occasionlly).

Hydro billing meters read wattage. As long as the voltage stays the
same, doubling amperage doubles the meter reading. But if the voltage
goes up by 5%, and the amperage goes down by a factor such that
voltage X amps stays the same (slightly less than 5%), the meter
reading (and hence the bill) will be the same.

Everett M. Greene

unread,
Jul 26, 2001, 9:37:01 PM7/26/01
to
"CBHVAC" <in...@carolinabreezehvac.com> writes:
> And what part of volts X Amps did you miss?
>
> That is actually watts BTW...

Actually, its volt-amperes or apparent power.

watts = volts X amps X powerfactor

> Tell you what...figure this one out then, IF the AMPERAGE used is NOT what
> runs the bill up....
>
> Why is it that a 30 RLA 220VAC motor uses the same amount of voltage, as a
> 10RLA 220VAC motor, drives the same load, does the same amount of work, but
> costs more to run? Both have the same service factor.
>
> Its not rocket science.

As you say...

> Volt: A unit of electrical potential, or pressure.
>
> Ampere (Amp): A unit of measurement for rate of current flow.
>
> Current: The flow of an electrical charge through a conductor with the
> ability to overcome resistance and perform work.
>
> Watt: A unit of electrical power, directly converted to work, the product of
> voltage and amperage. 746 watts are equal to one HP.
>
> Work: The transfer of energy from one object to another, measured in force
> multiplied by distance, or foot pounds.
>
> That pretty much sums it up..its not the voltage that the meter reads, its
> the amperage used. 220VAC, is 220VAC, or VDC even, the load, however, is
> rated in amps...keep adding things that use power, and the voltage rating
> remains the same, (generally), but the amperage draw increases.
>
> I never claimed to be an electrician...

That's a good thing...

>but ....its not rocket science.
>
> Amperage use is directly related to a utility bills amount...
> he said it, and I did as well, in simpler terms.

The utilities use a watthour meter to measure your power
usage. It's been many years since my power lab days, but
wattmeters measure both the voltage /and/ current to
produce a power reading. A true wattmeter has to correct
for power factor while a volt-ampeter meter doesn't.

It's possible that the utility meters are working on the
idea that the voltage is approximately constant and just
measure (and time integrate) the current.

Darrel

unread,
Jul 26, 2001, 8:18:44 PM7/26/01
to

"CBHVAC" <in...@carolinabreezehvac.com> wrote in message
news:98N77.2075$z%.83489@eagle.america.net...

> And what part of volts X Amps did you miss?
>
> That is actually watts BTW...
>
> Tell you what...figure this one out then, IF the AMPERAGE used is NOT what
> runs the bill up....
>
> Why is it that a 30 RLA 220VAC motor uses the same amount of voltage, as a
> 10RLA 220VAC motor, drives the same load, does the same amount of work,
but
> costs more to run? Both have the same service factor.


Because the 30 RLA 220VAC is less efficient, converting less of the power
consumed to useful work performed. This could be due to many things,
including cheaper materials (bearings?), poorer design, or being designed
for a different application (higher starting load or different duty cycle).


>
> Its not rocket science.
>
> Volt: A unit of electrical potential, or pressure.
>
> Ampere (Amp): A unit of measurement for rate of current flow.
>
> Current: The flow of an electrical charge through a conductor with the
> ability to overcome resistance and perform work.
>
> Watt: A unit of electrical power, directly converted to work, the product
of
> voltage and amperage. 746 watts are equal to one HP.
>
> Work: The transfer of energy from one object to another, measured in force
> multiplied by distance, or foot pounds.
>

And don't forget .....
Resistance: A physical attribute of a material, and which detemines how
much current flows for a given voltage through that material.

Resistance varies with temperature.
Transmission lines have resistance asoociated with them. That is why the
power company uses high voltage for transmission over long distances to
residential areas, then steps it down with transformers at or near the
destination. Power losses are calculated as current squared times resistance
(P=I^2 x R). With higher voltages, they can transmit the same power with
less loss, because the losses are linear with respect to voltage, but
squared with respect to current,

As the days got warmer, the resistance increased in the transmission lines
and the voltage at the service location dropped as a reault.

The power company was still maintaining the same voltage at their
measurement location, but less voltage was present at the home due to the
higher losses induced in the transmission lines during the hotter days.

Also, in addition to the air temperature, the higher demand for power in the
hotter months caused a higher current flow, which drove up the temperature
of the transmission line even more as the resistance of the power lines
resulted in more resistive heating of the lines themselves.

>
> That pretty much sums it up..its not the voltage that the meter reads, its
> the amperage used. 220VAC, is 220VAC, or VDC even, the load, however, is
> rated in amps...keep adding things that use power, and the voltage rating
> remains the same, (generally), but the amperage draw increases.
>
> I never claimed to be an electrician...but ....its not rocket science.

Actually, it's physics, which is present in great quantities in rocket
science.

And the meter doesn't directly measure current _or_ voltage. It is driven
by magnetic flux, which is proportional to power. Changing either voltage
or current such that total power is changed will change the rate at which
the meter registers usage.


>
> Amperage use is directly related to a utility bills amount...he said it,
and
> I did as well, in simpler terms.
>

Not amperage, power. That's why the meter is properly known as a
kilowatt-hour meter.

CBHVAC

unread,
Jul 27, 2001, 12:24:45 AM7/27/01
to
Like I said, I never claimed to be an electrician, dont want to be one, dont
want, or need the license to be one in this state since its illegal in NC
for the HVAC company to hook the final electrical connections to the units.
If I was wrong, and it seems I was told incorrect information from a Duke
power employee, then I stand corrected. There is no need for any of us to
get smart assed. Its no wonder this group get trolled as hard as it does.


--

Calvin Henry-Cotnam

unread,
Jul 27, 2001, 8:31:41 AM7/27/01
to
Chris Lewis (cle...@nortelnetworks.com) said...

>
>Generally speaking, "modern" computers (and much else that might be
>called "sensitive electronics") don't care that much.
>
>Many are designed to operate with anything from 90V-250V and 50-60Hz,
>without the user switching it in any way. This is due to the way
>switching power supplies work.

Very true, my laptop computer, my cam-corder, and my electric razor
are three items I can use in Europe with only a plug converter - no
transformer needed as they work on the 90V-250V range (the razor can
actually be directly plugged into a 12VDC outlet in a car as well!)

Don Klipstein

unread,
Jul 29, 2001, 10:06:28 PM7/29/01
to
In article <20010726.7...@mojaveg.nodomain>, Everett M. Greene wrote:
>
>The utilities use a watthour meter to measure your power
>usage. It's been many years since my power lab days, but
>wattmeters measure both the voltage /and/ current to
>produce a power reading. A true wattmeter has to correct
>for power factor while a volt-ampeter meter doesn't.
>
>It's possible that the utility meters are working on the
>idea that the voltage is approximately constant and just
>measure (and time integrate) the current.

Utilities use a true watt-hour meter to measure energy consumption.
These meters do a good job of accounting for power factor by doing a good
job of integrating over time the instantaneous product of voltage and
current. If there was no inertia in the dial or other moving parts, you
would even see it run backwards for a fraction of each half cycle (120
times a second) for the portions of each half-cycle where voltage and
current were in the opposite direction.

That higher reactive lagging amp motor costing more to run driving the
same load must be less efficient and also drawing more "in-phase" or
"resistive" or "real" amps. More amps of any kind will increase watts
consumed by the wiring between the meter and the load, but that is usually
only significant where the wiring is too small for the higher current
load.

Heck, if watthour meters billed you for reactive power, then the power
companies would not bother commercial and industrial customers about
maintaining good power factor. (Power companies need to have their
wiring large enough to carry whatever amps are "consumed" whether
real or reactive.) Turning a geenrator does not require nearly as much
work to produce a reactive amp as is required to produce an "in-phase" amp.
If power companies billed people for reactive "power", there are enough
people in the know about this to start a world-class uproar. All those
people buying fluorescent lights to replace incandescents are counting on
being billed only for the real power consumption, for one thing.

- Don Klipstein (d...@misty.com)

Terry Kennedy

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Jul 29, 2001, 11:14:08 PM7/29/01
to
In alt.home.repair Chris Lewis <cle...@nortelnetworks.com> wrote:
> Generally speaking, "modern" computers (and much else that might be
> called "sensitive electronics") don't care that much.
>
> Many are designed to operate with anything from 90V-250V and 50-60Hz,
> without the user switching it in any way. This is due to the way
> switching power supplies work.

For the most part, this is true. However, many switch-mode supplies have
an area of uncertainty in the middle part of that voltage range, where they
will get confused. For example, a "universal" switcher fed from 120 with a
spike to 150V may well switch into high-range input and then lock up (stop
switching) when the voltage goes back to nominal. Cisco has had this prob-
lem on some of their 2900XL switches.

> Code says that the power to the house is supposed to be within 5 or 6% of
> nominal 240/120V. 130V really isn't that far off. So, if it is _really_
> 130V, I'd expect relatively little problem except for lightbulbs.

Indeed. And a point I didn't see explicitly made previously is that any
losses in the utility transmission plant (before the user's meter) are the
utility's [financial] problem - the user's meter only measures power going
throuh it, not any "lost" before it.

The only issues (assuming a properly-functioning installation, no loose
neutrals, etc.) are:

1) decreased efficiency (= higher bills) for equipment working at one
end or the other of the allowable voltage range.

2) decreased life for things like light bulbs

If either of these are a problem, it's possible to install something
like a variable-tap autotransformer to compensate. However, it is also
not 100% efficient, and is a non-trivial expense as well (for a large
unit, at least). So you have to evaluate the trade-offs. Most people just
use the higher-voltage light bulbs...

Terry Kennedy http://www.tmk.com
te...@tmk.com New York, NY USA

Chris Lewis

unread,
Jul 30, 2001, 1:14:16 PM7/30/01
to
According to Terry Kennedy <te...@gate.tmk.com>:

> In alt.home.repair Chris Lewis <cle...@nortelnetworks.com> wrote:

> For the most part, this is true. However, many switch-mode supplies have
> an area of uncertainty in the middle part of that voltage range, where they
> will get confused. For example, a "universal" switcher fed from 120 with a
> spike to 150V may well switch into high-range input and then lock up (stop
> switching) when the voltage goes back to nominal. Cisco has had this prob-
> lem on some of their 2900XL switches.

I'm under the impression that most wide range switch supplies don't have
"modes" per-se, they just operate at whatever voltage they're presented
with, and modulate (via regulator circuitry) the drivers so that the
output filters deliver the desired output voltage. No mode detection or
switch circuitry required, just drive components capable of taking the
highest permissible input voltage, and enough current to provide enough
oomph at the lower end.

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