60 Hz measurement party
On 6/26/11 10:38 AM, Poul-Henning Kamp wrote:
My idea for measuring this, was to measure the time from the
utc second from a GPS receiver to the first zero-crossing of
the grid, and try plot Magnus and my measurements together.
So, to make this easy on folks..
Seems the easiest PC hardware thing would be to use a sound card input..
left input is the 1pps, right input is 50/60Hz derived from some local
source (a wire hanging out is probably enough, but noisy.. a transformer
or capacitor coupling from power line would be better)..
We could have a little application that runs and grabs, say, 10 seconds
worth of sound card data, figures out the phase, and logs it (or does a
cURL to send it to a website as a HTTP POST).
Even better would be a little dedicated widget that does it. I wonder
if one of those sub-$100 retail plug in servers (like the POGO plug)
could do it.
I think if we could make the "end user price" <$100, and it's truly plug
and play (i.e. not a "get this from place A, and find part B surplus,
and make a cable, etc.), we could probably get a bunch of people to just
try it. I sure would, and I know a bunch of people at work for which
this is in the "yeah, I'd do it as a toy" kind of category, as long as
it's less than, say, a couple hours to fool with it.
On Jun 25, 2011, at 7:31 PM, Jim Lux wrote:
although it's a lot easier if one of the links is down and they're running with the ocean return path.
Ocean return path? Please say more.
I picture a gigantic carbon electrode stuck in the ocean by a power station - rather like the core of a really large "D" cell.
That sounds like a recipe for excitement - DC current into seawater should generate hydrogen on one and and oxygen on the other electrode. At 3000 amps, rather a lot of it.
As for monitoring 60 Hz, I was doing some on line research, and found some interesting power line frequency meters at:
http://www.laurels.com/frequency.htm
Surprisingly affordable (less than $300).
Tom Frank
As for monitoring 60 Hz, I was doing some on line research, and found some interesting power line frequency meters at:
http://www.laurels.com/frequency.htm
Surprisingly affordable (less than $300).
Tom Frank
For this experiment you want an [accumulated] phase error meter,
not a line frequency meter. Remember, NERC is not dramatically
changing the 60 Hz frequency; the proposal is simply to eliminate
the steering that used to keep the cycles roughly aligned with UTC.
So a 3 or 4 or 5 digit sampling frequency counter will not reveal
the change. But over hours or days a mains connected kitchen
clock compared with your cell phone, will. In general, to see the
effect, you want something that faithfully tracks the phase and
compares it to a reference that's at least 1 ppm accurate.
Another approach, the one I use, is to continuously compare
60 Hz phase against UTC using a TIC, handling rollovers, etc.
/tvb
Will, and the rest of you fascinated by power distribution,
A big synchronous motor allows its power factor to be changed by
changing the field current for a given load. The motor can be
adjusted to look like a resistive load instead of inductive, or
even capacitive to correct plant power factor. Look it up.
Industrial power consumers are charged extra for power factors
less than unity because the distribution system must carry more
current for the same watts as the power factor departs from
unity.
Induction motors have inductive power factors because there must
be slip between the rotating field and the speed of the rotor.
Synchronous motors don't have slip, just phase angle. Zero angle
looks like a resistive load, yes?
The compressors don't have to run in sync.
Best,
Bill Hawkins
(who heaves a nostalgic sigh just thinking about those fine old
engines of progress)
-----Original Message-----
From: Will Matney
Sent: Sunday, June 26, 2011 1:11 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] 60 Hz measurement party
I quite like your generator description of "huge rotating lumps of
copper-ensnarled iron". It brings me back to around 20 years ago, when I
was a plant electrician at an older railcar manufacturer. They had huge
open-frame synchronous motors, from around the 1930's, that ran their air
compressors, and why they used this type of motor is anybodies guess. If I
remember right, they were rated at around 200 HP, or so, and were about 8
feet in diameter. The rotor shaft was mounted on huge babbit bearings upon
concrete pillars, and about 1/3 of the motor sat in a pit in the concrete
floor. I used to have to repair the brushes on the slip rings constantly,
until I talked the boss into adding a shunt across the n.o. contacts on the
250 Vdc contactors to quench any arcing. The motors stator itself ran on
4160 Vac. Would the other compressors have to run in sync somehow, as all
of them had these motors, just some a little smaller than the others? They
drove large single cylinder compressors that fed something like a 6 inch
air line (pipe). However, they all did not run at once, and they only did
when there was a larger demand for air. Timing is the only thing I can lay
this to, and was wondering about it.
Best,
Will
On 6/26/11 6:29 PM, Thomas A Frank wrote:
On Jun 25, 2011, at 7:31 PM, Jim Lux wrote:
although it's a lot easier if one of the links is down and they're running with the ocean return path.
Ocean return path? Please say more.
I picture a gigantic carbon electrode stuck in the ocean by a power station - rather like the core of a really large "D" cell.
Not far from the truth, actually.. cast iron electrodes at the north
end buried in a 2 mile diameter ring. iron alloy electrodes in concrete
in the ocean at the south end..
Electrodes :
At Celilo : the ground electrode is located 10.6 km from
the converter station, in Rice Flates. The electrode is designed as a
ring type 3255 m circumference, 1067 cast iron anodes, and 2' X 2' coke
backfill is used. Total resistance in 2 parallel electrode lines and
ground electrode = 0.43 ohms.
At Sylmar : the sea electrode is located 48 km from the
converter station, in the Pacific Ocean and consists of a linear array
of 24 horizontal electrode elements made up of silicon-iron alloy rods
suspended 0.5 to 1 m above the ocean bottom and located within concrete
enclosures. Total resistance in 2 parallel electrode lines and sea
electrode = 1.13 ohms.
That sounds like a recipe for excitement - DC current into seawater should generate hydrogen on one and and oxygen on the other electrode. At 3000 amps, rather a lot of it.
I imagine they keep the current density low enough that the gas is
absorbed into the water as it's evolved. But yes.. a fascinating concept.
And I'm curious where, exactly, that DC line to the ocean runs. (since
I live between Sylmar and the ocean, as do about 10 million other people)
I guess I can draw a circle of radius 48km from Sylmar..
At Sylmar : 2 X 644 mm2 ACSR conductors in parallel are used for the
first 35 km, supported by the 230 kV line towers. For the remaining 13
km, two parallel paper-insulated underground cables are used, each with
a 633 mm2 Cu-conductor.
I just have to look for a set of towers with a single duplex cable.
(actually a bit of googling found a report
www.kentercanyon.org/index.php/download-public-docs/doc/25/raw
)
Bill,
I never did set back and think why they used them, but that would make
sense. The new plant engineer they hired, during my time there, talked them
into installing a new power house (air compressor system) in the paint
department. However, he had ordered screw compressors, running on 460 V, 3
phase motors. He was cursed by every electrician on that job over the big
cables that had to be pulled for the current they consumed.
I also wondered if it could have had something to do with the starting
torque of the sync motors over induction motors. Those old compressors had
flywheels on them almost the diameter of the motors that ran them, and it
would take a huge amount of torque to set them to turning, especially when
the compressor was pumping into a pipe full of compressed air. It would be
about like trying to start or run the engine in your car with the tail pipe
stopped up.
Thanks,
Will
*********** REPLY SEPARATOR ***********
On 6/26/2011 at 10:12 PM Bill Hawkins wrote:
Will, and the rest of you fascinated by power distribution,
A big synchronous motor allows its power factor to be changed by
changing the field current for a given load. The motor can be
adjusted to look like a resistive load instead of inductive, or
even capacitive to correct plant power factor. Look it up.
Industrial power consumers are charged extra for power factors
less than unity because the distribution system must carry more
current for the same watts as the power factor departs from
unity.
Induction motors have inductive power factors because there must
be slip between the rotating field and the speed of the rotor.
Synchronous motors don't have slip, just phase angle. Zero angle
looks like a resistive load, yes?
The compressors don't have to run in sync.
Best,
Bill Hawkins
(who heaves a nostalgic sigh just thinking about those fine old
engines of progress)
-----Original Message-----
From: Will Matney
Sent: Sunday, June 26, 2011 1:11 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] 60 Hz measurement party
I quite like your generator description of "huge rotating lumps of
copper-ensnarled iron". It brings me back to around 20 years ago, when I
was a plant electrician at an older railcar manufacturer. They had huge
open-frame synchronous motors, from around the 1930's, that ran their air
compressors, and why they used this type of motor is anybodies guess. If I
remember right, they were rated at around 200 HP, or so, and were about 8
feet in diameter. The rotor shaft was mounted on huge babbit bearings upon
concrete pillars, and about 1/3 of the motor sat in a pit in the concrete
floor. I used to have to repair the brushes on the slip rings constantly,
until I talked the boss into adding a shunt across the n.o. contacts on
the
250 Vdc contactors to quench any arcing. The motors stator itself ran on
4160 Vac. Would the other compressors have to run in sync somehow, as all
of them had these motors, just some a little smaller than the others? They
drove large single cylinder compressors that fed something like a 6 inch
air line (pipe). However, they all did not run at once, and they only did
when there was a larger demand for air. Timing is the only thing I can lay
this to, and was wondering about it.
Best,
Will
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On 6/26/11 8:23 PM, Jim Lux wrote:
I just have to look for a set of towers with a single duplex cable.
(actually a bit of googling found a report
www.kentercanyon.org/index.php/download-public-docs/doc/25/raw
)
OK.. the electrodes are about a mile off shore from Gladstone's-4-Fish
on PCH (for those of you familiar with the area). The onshore vault is
in their parking lot.
I wonder what it looks like, and how deep the water is? ANd whether one
would want to dive there when it's turned on?
Fascinating.. it runs 20 hours a year..
There's a some folks concerned about the overhead line going near/over a
school. I'll bet they didn't actually know the line is unenergized
virtually all the time.
Here's another thought on all of this. How will this effect the newer
electronic watthour meters at peoples homes? I remember looking at the
schematics on one of these, and I don't remember seeing an internal time
base, crystal, or resonator in the circuit, so I suppose they might get
their timing from the 60 Hz line. Lets say that the frequency is slowed a
small amount, and over the year, they lose a little, which amounts to
pocket change per customer they lost, but multiply that by all the people
using it, well that's a lot of saw bucks. Also, if it was the reverse, and
the frequency was sped up by a small amount, that might translate into
paying out more, as I'm not sure exactly how those new meters work. The
only way I could see this happening, would be that the meters were not
using an internal timebase of some sort, thus depending on the line
frequency for timing, and raising and lowering with the line frequency over
a time period. Any thoughts on this?
Best,
Will
*********** REPLY SEPARATOR ***********
On 6/26/2011 at 8:02 PM Tom Van Baak wrote:
As for monitoring 60 Hz, I was doing some on line research, and found
some interesting power line frequency meters at:
For this experiment you want an [accumulated] phase error meter,
not a line frequency meter. Remember, NERC is not dramatically
changing the 60 Hz frequency; the proposal is simply to eliminate
the steering that used to keep the cycles roughly aligned with UTC.
So a 3 or 4 or 5 digit sampling frequency counter will not reveal
the change. But over hours or days a mains connected kitchen
clock compared with your cell phone, will. In general, to see the
effect, you want something that faithfully tracks the phase and
compares it to a reference that's at least 1 ppm accurate.
Another approach, the one I use, is to continuously compare
60 Hz phase against UTC using a TIC, handling rollovers, etc.
/tvb
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
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signature database 5851 (20110206) __________
In message 4E07F7C7.9070000@earthlink.net, Jim Lux writes:
That sounds like a recipe for excitement - DC current into
seawater should generate hydrogen on one and and oxygen on the other
electrode. At 3000 amps, rather a lot of it.
Actually you get chlorine gas at one end, can't remember which.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
In message 201106270013470285.1B239AEA@smtp.citynet.net, "Will Matney" writes
:
Here's another thought on all of this. How will this effect the newer
electronic watthour meters at peoples homes? I remember looking at the
schematics on one of these, and I don't remember seeing an internal time
base, crystal, or resonator in the circuit, so I suppose they might get
their timing from the 60 Hz line.
Modern microcontrollers contain a on-chip resonator, typically 8MHz,
which is surprisingly stable, often a lot more stable than the mains
frequency.
Electricity meters are usually only precise to 1 or 2%.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.