Kill-a-Watt surprises

[D Yuniskis]

Phil Hobbs wrote:

Yes, of course. But a VA-hour is a meaningless unit unless you know the
power factor--real power costs money and fuel, whereas (apart from
transmission losses) reactive power just sloshes back and forth cycle by

This one is a keeper -----------------^^^^^^^^^^^^^^^^^^^^^^^^^^^
;-)

cycle. That's why multiplying it by any period of time longer than a
cycle is meaningless.

 

[David Nebenzahl]

On 11/4/2009 10:36 AM D Yuniskis spake thus:

Phil Hobbs wrote:

Yes, of course. But a VA-hour is a meaningless unit unless you know the
power factor--real power costs money and fuel, whereas (apart from
transmission losses) reactive power just sloshes back and forth cycle by

This one is a keeper -----------------^^^^^^^^^^^^^^^^^^^^^^^^^^^
;-)

cycle. That's why multiplying it by any period of time longer than a
cycle is meaningless.

Ah, so electricity really *is* like water, eh? (Volts = pressure, amps =
flow.)


--
Who needs a junta or a dictatorship when you have a Congress
blowing Wall Street, using the media as a condom?

- harvested from Usenet

 

[Ron]

David Nebenzahl wrote:

On 11/4/2009 10:36 AM D Yuniskis spake thus:

Phil Hobbs wrote:

Yes, of course. But a VA-hour is a meaningless unit unless you know
the power factor--real power costs money and fuel, whereas (apart
from transmission losses) reactive power just sloshes back and forth
cycle by

This one is a keeper -----------------^^^^^^^^^^^^^^^^^^^^^^^^^^^
;-)

cycle. That's why multiplying it by any period of time longer than a
cycle is meaningless.

Ah, so electricity really *is* like water, eh? (Volts = pressure, amps =
flow.)


I once knew someone who always switched the wall sockets off when not is

use to prevent the electrickery flowing out of the open socket.

Ron

 

[Ron]

Geoffrey S. Mendelson wrote:

Ron wrote:

I once knew someone who always switched the wall sockets off when not is
use to prevent the electrickery flowing out of the open socket.

I was told by someone that they were worried about the radiation from
their (receive only) satellite dish.

Geoff.
Thats why they used to come with instructions for making a tinfoil hat

 

[Geoffrey S. Mendelson]

Ron wrote:

I once knew someone who always switched the wall sockets off when not is
use to prevent the electrickery flowing out of the open socket.

I was told by someone that they were worried about the radiation from
their (receive only) satellite dish.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM

 

[Jeff Layman]

N_Cook wrote:

I bought a set-top box (UK Freeview) and thought to myself
"hang on a bit the box is as warm with green LED on as on red standby"
I measured consumed watts in both states and standby is 80 percent of the
on state. I put in a hard on/off switch , data held in EEProm or whatever
and no difference in function except programme info pages takes a couple
of minutes to gather

What is meant by "standby"? You may think you know (as I thought I did,
too), but it isn't that simple. See here:
http://arstechnica.com/gadgets/news/2009/02/sony-lcd-exceeds-energy-star-power-draw-75-of-time.ars

It's not just Sony. I queried Panasonic about the regular clicking from my
LCD TV, even when it was in "Standby" mode, and also the less-than-green
readings I was getting from a power meter attached to it (15w in standby,
and 30w when it clicked. I do not know what the power factor of the TV is,
so do not know how these figures correlate with Panasonic's stated standby
consumption of 0.3w, but they don't seem very different from those reported
with the Sony). This was their reply:

"In response, I would advise that first please ensure the SETUP menu option
for “auto search in standby” is switched off. (this is in the “System
Update” SETUP menu option.

Turning off this option will also stop intermittent clicking from the TV
that are caused as the internal PSU relays are turned on to allow the
Freeview decoder to work for software updating.

2.) Please note that the set takes approximately 2 minutes for all the PSU
relays to click off and so the power will only read 0.5W after this time.

3.) Ensure that the power meter used can read the power factor of the unit
required to calculate AC power and is using this to calculate power.

4.) Ensure the meter is capable of accurately reading 0.5W; many meters
cannot go this low. Please refer to the meter’s specification."

That reply was open and very helpful, but (a) "auto search in standby" is
the default condition (b) there is no mention of this in the manual (c) I
still do not know how often the TV goes into auto search mode, for how long,
and what the actual power consumption is in this mode.

I have now taken to switching off at the plug when the TV is not in use.
Info on the DTG pages let me know when to leave the TV in standby/autosearch
for an update.

It makes me wonder just how accurate many other low consumption "standby"
figures are.

--
Jeff

 

[AZ Nomad]

On Wed, 4 Nov 2009 22:16:35 -0000, Jeff Layman <jmlayman@invalid.invalid> wrote:

N_Cook wrote:

I bought a set-top box (UK Freeview) and thought to myself
"hang on a bit the box is as warm with green LED on as on red standby"
I measured consumed watts in both states and standby is 80 percent of the
on state. I put in a hard on/off switch , data held in EEProm or whatever
and no difference in function except programme info pages takes a couple
of minutes to gather

What is meant by "standby"? You may think you know (as I thought I did,
too), but it isn't that simple. See here:
http://arstechnica.com/gadgets/news/2009/02/sony-lcd-exceeds-energy-star-power-draw-75-of-time.ars

It's not just Sony. I queried Panasonic about the regular clicking from my
LCD TV, even when it was in "Standby" mode, and also the less-than-green
readings I was getting from a power meter attached to it (15w in standby,
and 30w when it clicked. I do not know what the power factor of the TV is,
so do not know how these figures correlate with Panasonic's stated standby
consumption of 0.3w, but they don't seem very different from those reported
with the Sony). This was their reply:

that's impressive. I just took my killowatt from storage and measured a few
devices. 50" panasonic plasma: on 340watts, off less than 1. 32" polaroid lcd:
130 Watts on, less than 1 off.

diskless computer for mythtv remote (1.8ghz amd64, 2G ram), 25 watts on, no
standby mode. Scientific Atlanta HD cable box, 20 watts on/standby.

No surprises. I knew the cable box was a pig, about the same as a computer
left running 24x7.

 

[David Nebenzahl]

On 11/4/2009 11:56 AM Ron spake thus:

David Nebenzahl wrote:

Ah, so electricity really *is* like water, eh? (Volts = pressure, amps =
flow.)

I once knew someone who always switched the wall sockets off when not is
use to prevent the electrickery flowing out of the open socket.

Don't laugh; way back when, they (you know, "they" who put light bulbs
inside refrigerators and such) used to sell outlet covers for nervous
customers worried about just that.


--
Who needs a junta or a dictatorship when you have a Congress
blowing Wall Street, using the media as a condom?

- harvested from Usenet

 

[David Brodbeck]

N_Cook wrote:

I bought a set-top box (UK Freeview) and thought to myself
"hang on a bit the box is as warm with green LED on as on red standby"
I measured consumed watts in both states and standby is 80 percent of the on
state. I put in a hard on/off switch , data held in EEProm or whatever and
no difference in function except programme info pages takes a couple of
minutes to gather

I checked my VCR/DVD player one day and found that it drew exactly the
same amount of power when "off" as it did when "on". The power button
was essentially just a placebo.

 

[David Lesher]

"William Sommerwerck" <grizzledgeezer@comcast.net> writes:

Your electric meter measures watts, not VA. If you know the power
factor, you can convert these VA measurements to watts and eventually
to your cost of electricity. The kill-a-watt meter shows both VA and
watts (as well as PF).

My understanding was that the watt-hour meter actually measure VA-hours. I
asked the electric company once, and that said that was the case. But I
wasn't speaking with an engineer.

It measures true watt-hours. A bad PF device will cost you only SLIGHTLY
more in losses than if it had 1.0 PF. [Increased I, ergo more I^2R]

You can look up "Electricity meter" in Wikipedia..
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

 

[Franc Zabkar]

On Mon, 2 Nov 2009 14:13:27 -0800, "William Sommerwerck"
<grizzledgeezer@comcast.net> put finger to keyboard and composed:

My understanding was that the watt-hour meter actually measure VA-hours. I
asked the electric company once, and that said that was the case. But I
wasn't speaking with an engineer.

FWIW, Energy Australia responded to my query as follows:

"Most residential classification customers are metered by a spinning
disc meter, or a basic electronic meter which does not have enough
'smarts' in the meter device to enable billing to be carried out at a
KVA pricing.

Currently small customers are billed on KWh pricing, and KVA Demand
pricing usually relates to large commercial and industrial
installations where poor power factor may impact upon the EA network,
and there may be an economic billing benefit in the customer pricing
to ensure that Power factor is closer to Unity."

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Franc Zabkar]

On Mon, 2 Nov 2009 09:00:58 -0800, "William Sommerwerck"
<grizzledgeezer@comcast.net> put finger to keyboard and composed:

Its been pointed that you don't really need a watt or watt-hour meter to
save money -- you just turn off things you're not using.

This is not altogether true.

My electric bill was ridiculous, so I started checking. I'd been too lazy to
regularly turn off my A/V system's equipment, which includes a number of
vampire devices.

I was surprised to discover that the Parasound controller pulled 30VA, even
when not turned on. And a Lexicon CP-3plus drew 20VA, simply in standby. As
I rarely use it, I turned the standby switch to "off".

Calculate the VA consumed by the X2 EMI suppression capacitor across
the mains terminals.

For example, a 2.2uF cap across a 240VAC 50Hz supply consumes 39.8VA:

http://www.google.com/search?q=240+x+240+x+2+x+pi+x+50+x+2.2E-6

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[William Sommerwerck]

My understanding was that the watt-hour meter actually measure VA-hours.
I
asked the electric company once, and that said that was the case. But I
wasn't speaking with an engineer.

FWIW, Energy Australia responded to my query as follows:

"Most residential classification customers are metered by a spinning
disc meter, or a basic electronic meter which does not have enough
'smarts' in the meter device to enable billing to be carried out at a
KVA pricing.

Currently small customers are billed on KWh pricing, and KVA
Demand pricing usually relates to large commercial and industrial
installations where poor power factor may impact upon the EA network,
and there may be an economic billing benefit in the customer pricing
to ensure that Power factor is closer to Unity."

This is really confusing. Looking solely at the second paragraph, the
implication is that industrial metering is at the VAh level, not Wh.

I don't think this person really knows what he's talking about. The fact
that his statements are redundant ("a basic electronic meter which does not
have enough 'smarts' in the meter device") and jargony strongly suggests
this.

Nevertheless, thanks for asking. I think I'll call the Seattle utility
again.

 

[Sylvia Else]

William Sommerwerck wrote:

My understanding was that the watt-hour meter actually measure VA-hours.
I
asked the electric company once, and that said that was the case. But I
wasn't speaking with an engineer.

FWIW, Energy Australia responded to my query as follows:

"Most residential classification customers are metered by a spinning
disc meter, or a basic electronic meter which does not have enough
'smarts' in the meter device to enable billing to be carried out at a
KVA pricing.

Currently small customers are billed on KWh pricing, and KVA
Demand pricing usually relates to large commercial and industrial
installations where poor power factor may impact upon the EA network,
and there may be an economic billing benefit in the customer pricing
to ensure that Power factor is closer to Unity."

This is really confusing. Looking solely at the second paragraph, the
implication is that industrial metering is at the VAh level, not Wh.

It may well be, and for the reason given, which seems valid.

I don't think this person really knows what he's talking about. The fact
that his statements are redundant ("a basic electronic meter which does not
have enough 'smarts' in the meter device") and jargony strongly suggests
this.

Perhaps a bit clumsy, but I think the word meter is being used in two
different ways. The scribe probably wasn't employed for his writing talent.

Sylvia.

 

I used to work for a submetering outfit and Kill-a-watt was cool.
We tried real hard to find as cheap a doppler ultrasound flowmeter
for water and fuel but the lowest we got was two grand.

But my stud finder is ultrasound. THe only difference should be software.


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http://www.panix.com/~vjp2/vasos.htm http://www.facebook.com/vasjpan2
---{Nothing herein constitutes advice. Everything fully disclaimed.}---
[Homeland Security means private firearms not lazy obstructive guards]
[Urb sprawl confounds terror] [Phooey on GUI: Windows for subprime Bimbos]

 

[D Yuniskis]

vjp2.at@at.BioStrategist.dot.dot.com wrote:

I used to work for a submetering outfit and Kill-a-watt was cool.

I think there are competing products with better specs (?)

We tried real hard to find as cheap a doppler ultrasound flowmeter
for water and fuel but the lowest we got was two grand.

But my stud finder is ultrasound. THe only difference should be software.

No doubt partly due to market? E.g., someone makes a gizmo
used to check the integrity of (wooden) telephone poles:
attach to pole, wack pole with hammer, "listen" to
vibrations. Cool, eh? No doubt *very* expensive as
there are few companies interested in "telephone poles"
and, those that are, have deep pockets for this sort
of PM!

 

[David Brodbeck]

William Sommerwerck wrote:

This is really confusing. Looking solely at the second paragraph, the
implication is that industrial metering is at the VAh level, not Wh.

Industrial customers sometimes are required to pay extra if they have a
low power factor. This gives them an incentive to do their own power
factor correction instead of making it the power company's problem.