In message
That sounds like a dangerous idea to me. Lightning arrestors at service
entrances are designed to crowbar only for a cycle or so. As mentioned
earlier in this thread, residential distribution in the US nearly always
consists of a center-tapped balanced feed with the center tap grounded.
If you
Wonder if these cases could be used on social media to create enough
fear that there would be a market for AC crowbars capable of blowing
line/pole transformer HV fuses? There's a few hits with Google, mostly
for DC crowbars. Too bad relays are so slow.
Bill Hawkins
-Original Message-
HAHAHAHAHAHA. No,
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jeremy Nichols
Sent: Tuesday, January 3, 2017 11:48 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Line Voltage - USA
Did the utility replace
: [time-nuts] Line Voltage - USA
Did the utility replace the damaged equipment?
A friend lived in a building when the city crew working on a transformer put
440 on the line. It blew out all the electronics in 12 condos - mostly TVs.
I think toasters and refrigerators were OK. There wasn't any
Hi David. I've been told that in Canada the residential supply voltage in a
neighbourhood is often set to account for the voltage drop in typical
residential branch circuits.
The last time the supply voltage in my home was checked it read 125 volts from
each "service pole" to neutral or 250
On 4 January 2017 at 14:25, Dr. David Kirkby (Kirkby Microwave Ltd) <
drkir...@kirkbymicrowave.co.uk> wrote:
>
> I just phoned Tektronix and they want £160 (GBP) + VAT to calibrate this
> 6000 count handheld DMM. Ouch. I will not bother with that.
>
Sorry, 60,000 touch - 4 3/4 digits.
d Kirkby (Kirkby Microwave Ltd)
> Sent: 04 January 2017 13:42
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Line Voltage - USA
>
> I measured my voltage overnight in a peak hold at 255.10 V RMS as close to
> the meter as I could.
>
> _
Time to call your supply co.
Dave
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David
Kirkby (Kirkby Microwave Ltd)
Sent: 04 January 2017 13:42
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Line Voltage - USA
On 4 January 2017 at 09:34, Poul-Henning Kamp wrote:
>
>
> >Do you have a reference to this +6%? I've heard from various sources that
> >the UK is 230 -6%/+10%. If the EU dictates otherwise, then I'm certainly
> >over the 6% limit. I may or may not be over the 10%
Hi
> On Jan 4, 2017, at 3:42 AM, Hal Murray wrote:
>
>> Did the utility replace the damaged equipment?
>
> A friend lived in a building when the city crew working on a transformer put
> 440 on the line. It blew out all the electronics in 12 condos - mostly TVs.
> I
> How much trouble do hams have with their insurance companies?
Typically very little if you have a rider to cover it. Costs a few $ a year
Had my basement flood a number of years back and take out a few k worth of
vintage computer gear. Not a problem. Covered to replacement cost.
I have a
measurement; Dr. David Kirkby
(Kirkby Microwave Ltd)
Subject: Re: [time-nuts] Line Voltage - USA
There was a transitional range, but I belive it has expired.
In 240V countries it was -6%/+10%.
In 220V countries it was -10%/+6%
___
time-nuts mailing list
In message
> Did the utility replace the damaged equipment?
A friend lived in a building when the city crew working on a transformer put
440 on the line. It blew out all the electronics in 12 condos - mostly TVs.
I think toasters and refrigerators were OK. There wasn't any question that
the city was
Did the utility replace the damaged equipment?
On Tue, Jan 3, 2017 at 9:33 PM Van Horn, David <
david.vanh...@backcountryaccess.com> wrote:
> I once had some odd equipment failures which we found out were caused by
> the line voltage being at 142V.
>
> This was in the mid 80's in Costa Mesa CA.
I once had some odd equipment failures which we found out were caused by the
line voltage being at 142V.
This was in the mid 80's in Costa Mesa CA. The tech they sent out told me they
had us on the wrong transformer tap.
Lowest I've seen was 70V in Hawaii, with everyone coming home about 5PM
Leap seconds only matter if you are counting seconds. The power
line isn't. As long as they keep the frequency near nominal, they
are fine.
-Chuck Harris
J wrote:
> Power utilities tweak the system frequency on a daily basis to keep MAINS
> powered clocks correct. I wonder what their
HI
> On Jan 3, 2017, at 6:59 PM, Hal Murray wrote:
>
>
> kb...@n1k.org said:
>> They sell a lot of 24 bit audio DAC’s into that sort of gear. Team them up
>> with some DSP and you get all sorts of interesting data. The “one number”
>> that counts is the fundamental ….
kb...@n1k.org said:
> They sell a lot of 24 bit audio DACâs into that sort of gear. Team them up
> with some DSP and you get all sorts of interesting data. The âone numberâ
> that counts is the fundamental â¦.
DAC?
There is a big market for high resolution ADCs in that area - one in
Power utilities tweak the system frequency on a daily basis to keep MAINS
powered clocks correct. I wonder what their correction strategy was for the
leap second?
On Tue, Jan 3, 2017 at 11:05 AM, Vlad wrote:
>
>
> Speaking about MAIN... I was interesting to see if "leap second"
Hi
Measuring line voltage for “official” purposes straight up with a lab grade
device that may
have a bandwidth of many KHz (or even 100’s of KHz) is generally not a good way
to go.
The line voltage is the value of the fundamental (50 or 60 Hz) sine wave. All
the other nonsense
that
On 2 January 2017 at 05:15, Jeremy Nichols wrote:
> Thank you for the detailed analysis, Bill. The voltage measurements I made
> in my garage laboratory were duplicated by the utility with their meter,
> which was connected at the service entrance.
I have just been chatting
I put some raw data here:
http://www.patoka.ca/OCXO/60HZ.logs.tar.Z
Unfortunately its not continuous, because of for some period of times my
machine was offline (software upgrades or my radio made some mess with
RF which affects the MCU and recordings. And I was busy with something
else
I noticed following information (source:
http://www.mainsfrequency.com/news.htm#2015_1):
Minimum and maximum mains frequency
To clarify the question "how stable is the mains frequency", data of the
last 13 months was analyzed (July 2011 to July 2012). The greatest
fluctuations occurred
Vlad
do you have that data for a longer period of time...say 3 to 6 months?
Dave
On 1/3/2017 11:05 AM, Vlad wrote:
Speaking about MAIN... I was interesting to see if "leap second" event
has correlation with MAIN frequency fluctuation
Here is graphs for the MAIN periods recorded. Note:
On 2 January 2017 at 18:14, Poul-Henning Kamp wrote:
>
> In message qnosgqvz...@mail.gmail.com>
> , Tim Shoppa writes:
>
> >What modern loads are actually sensitive to high (say, +10 to +20%) line
> >voltage?
>
> In EU you're supposed to have 230V +/- 6% in your
Speaking about MAIN... I was interesting to see if "leap second" event
has correlation with MAIN frequency fluctuation
Here is graphs for the MAIN periods recorded. Note: The data on the
charts is "smoothed" by Bezier curves
I could see some "surge" which starts to climb in December 30
htning rod protection.
73
Lee K9WRU
- Original Message -
From: Poul-Henning Kamp <p...@phk.freebsd.dk>
To: Discussion of precise time and frequency measurement <time-nuts@febo.com>,
Chuck Harris <cfhar...@erols.com>
Sent: Mon, 02 Jan 2017 12:55:58 -0500 (EST)
Subjec
In message
, Tim Shoppa writes:
>What modern loads are actually sensitive to high (say, +10 to +20%) line
>voltage?
In EU you're supposed to have 230V +/- 6% in your outlet.
The way this was arrived at was:
A lot of
What modern loads are actually sensitive to high (say, +10 to +20%) line
voltage?
Old incandescent light bulbs were among the most sensitive loads in the
past (so much so, that 130V light bulbs were commonly available from the
industrial suppliers).
I would naively expect the modern CFL's and
In message <586a8b40.4050...@erols.com>, Chuck Harris writes:
>Back in the dark ages of ~220V electrical distribution systems in
>Europe, the reaping due to unintentional grounding of a ~220V wire
>was so common and extreme, whole house ground fault interrupters
>were mandated for all
It's not a split phase system in US residential power, it is a
center tapped 240V single phase system. Split phase systems have
historically had a 45-90 degree phase difference between the split
phases. The US system, depending on which wire lead you take as
your reference, has a 0, or a 180
On Mon, Jan 2, 2017 at 4:49 AM, Bill Byrom wrote:
> Most US homes and small businesses are powered by what is commonly
> called a "split-phase" 240 V feed. The final distribution system
> transformer has a 240 V center-tapped secondary. The center tap is
> grounded, and three
Thank you for the detailed analysis, Bill. The voltage measurements I made
in my garage laboratory were duplicated by the utility with their meter,
which was connected at the service entrance. We each showed voltage in
excess of 126 VAC. Date from the (U of Tennessee) Frequency Disturbance
There are a couple of recent threads concerning the power line mains
voltage standards. After a bit of research and thinking, I have found
that this is a complex topic. The simple answer is:
* The standard in the US for the past 50 years has been 120/240 V +/- 5%
RMS at the service entrance to
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