Alternative Power sources - Dimmable Lights and Power Usage

Author

Dimmable Lights and Power Usage

Too_Many_Tools

2005-08-21, 4:21 pm

Do the dimmable lights (those that have three fixed settings where you
touch the metal lamp base to adjust them) use power when they are off?

If one wants dimmable lighting, what is the best type to install?

Thanks for any information you can offer.

TMT

Solar Flare

2005-08-21, 5:21 pm

They must use micropower to sense the touch but not enough to measure in
terms of household power. Can you feel any heat from them or the lamp lit
up? Energy cannot just disapear into nothing.

"Too_Many_Tools" <too_many_tools@yahoo.com> wrote in message
news:1124648733.420251.172180@g49g2000cwa.googlegroups.com...
> Do the dimmable lights (those that have three fixed settings where you
> touch the metal lamp base to adjust them) use power when they are off?
>
> If one wants dimmable lighting, what is the best type to install?
>
> Thanks for any information you can offer.
>
> TMT
>

Jim Baber

2005-08-21, 5:21 pm

Jim replys:

Too_Many_Tools wrote:

>Do the dimmable lights (those that have three fixed settings where you
>touch the metal lamp base to adjust them) use power when they are off?
>
>
Yes, these are electronic switches and they do require a very small
sensing circuit to tell when you touch them.

>If one wants dimmable lighting, what is the best type to install?
>
>
I am a firm believer in using CFL (Compact Fluorescent Light) wherever
you can and there are good variable CFL bulbs that will save a
considerable amount of money in the long term over the usual
incandescent bulbs, BUT, these are going to originally cost considerably
more than either incandescent or non variable CFL lights.

I have had good luck with them in my dining room fixture, and
particularly good luck in my ceiling fan's light fixtures where the fan
control came with a light dimmer function. These dimmers were
frequently accidentally used and when I had regular CFL bulbs in the 3
fan fixtures I have, they failed frequently. However once I put the
dimmable CFL bulbs in the fan fixtures, the problems went away and I
dropped each bulb wattage from 100 W. to 23 W. (9 bulbs total) By the
way, the CFL bulbs do last a lot better than incandescent bulbs in the
fans because they don't seem to be affected as much by the vibrations of
the fans.

I also have used these "variable CFL" bulbs in a bedside lamp that has
the kind of touch sensitive 4 way switch you mentioned at first quite
successfully. I also have one in a X-10 lamp module controlled light
that seems to function OK as far as dimming, at least whenever the
module decides to work, but the X-10 module itself is being it's usual
PIA self.

Hope this helps.

>Thanks for any information you can offer.
>
>TMT
>
>
>

danny burstein

2005-08-21, 6:21 pm

[ lots snipped ]

>Yes, these are electronic switches and they do require a very small
>sensing circuit to tell when you touch them.

>I am a firm believer in using CFL (Compact Fluorescent Light) wherever
>you can and there are good variable CFL bulbs that will save a
>considerable amount of money in the long term over the usual
>incandescent bulbs, BUT, these are going to originally cost considerably
>more than either incandescent or non variable CFL lights.

I can't find the OP's post here so don't know if the circuit
is hooked up to utility or off-grid power.

Compact fluorescents have _abysmal_ power factor ratings. Unlike with an
incandescent, where watts = volts*amperes (with a definitional power
factor of 100), you're going to see ugly figures.

I just checked a sylvana " 15 watt " reflector flood. The label
itself says it's 15 watts, but 0.26 amps. That 0.26 amps, if
in an incandescent (or 100 percent power factor) would
give you (0.26 times 120 = ) 31 watts. So the labeled PF is 50.

( my measurements showed it as 13 watts and 0.27 amps)

Depending on what's behind the scenes delivering power
to the circuit, that PF may, or may not, be an issue.

Given how "dimmers" work, I suspect (but have no measurements
to point to) that the PF would be even worse when cutting
the light down.
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

Steve Spence

2005-08-21, 9:21 pm

yep, I'm looking at my 14 watt CF, and my Kill-A-Watt is reporting a pf
of .57

Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

danny burstein wrote:
> [ lots snipped ]

>
> I can't find the OP's post here so don't know if the circuit
> is hooked up to utility or off-grid power.
>
> Compact fluorescents have _abysmal_ power factor ratings. Unlike with an
> incandescent, where watts = volts*amperes (with a definitional power
> factor of 100), you're going to see ugly figures.
>
> I just checked a sylvana " 15 watt " reflector flood. The label
> itself says it's 15 watts, but 0.26 amps. That 0.26 amps, if
> in an incandescent (or 100 percent power factor) would
> give you (0.26 times 120 = ) 31 watts. So the labeled PF is 50.
>
> ( my measurements showed it as 13 watts and 0.27 amps)
>
> Depending on what's behind the scenes delivering power
> to the circuit, that PF may, or may not, be an issue.
>
> Given how "dimmers" work, I suspect (but have no measurements
> to point to) that the PF would be even worse when cutting
> the light down.

danny burstein

2005-08-21, 10:21 pm

In <Im8Oe.15417$U63.11644@fe12.lga> Steve Spence <sspence@green-trust.org> writes:

>yep, I'm looking at my 14 watt CF, and my Kill-A-Watt is reporting a pf
>of .57

you wouldn't know how this related to use with a portable generator,
offhand, would you?

I tried asking the question of a couple of reasonably clueful generator
sales reps and they knew what I was talking about, but all scratched their
heads in ignorance...

In short, will the generator "see" the load based on VA, and thus
be pretty limited, or will it "see" the wattage?

And... if it's the VA figure, then does it waste all that extra fuel
making up for the power factor? If so, I'm actually better off using
incandescants than CFs.... (or close enough)

Enquiring minds want to know...

Thanks
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

Vaughn

2005-08-21, 11:21 pm

"danny burstein" <dannyb@panix.com> wrote in message
news:deb8pq$9bo$1@reader2.panix.com...
> In <Im8Oe.15417$U63.11644@fe12.lga> Steve Spence <sspence@green-trust.org>
> writes:
>
> In short, will the generator "see" the load based on VA, and thus
> be pretty limited, or will it "see" the wattage?
>
> And... if it's the VA figure, then does it waste all that extra fuel
> making up for the power factor? If so, I'm actually better off using
> incandescants than CFs.... (or close enough)

The bad power factor causes some inefficiencies, but you are still much
better off with the CF's compared to equilivant incandescent.

Vaughn

Steve Spence

2005-08-21, 11:21 pm

it's va * pf, and CF's are still the better deal.

Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

danny burstein wrote:
> In <Im8Oe.15417$U63.11644@fe12.lga> Steve Spence <sspence@green-trust.org> writes:
>
>
>
>
> you wouldn't know how this related to use with a portable generator,
> offhand, would you?
>
> I tried asking the question of a couple of reasonably clueful generator
> sales reps and they knew what I was talking about, but all scratched their
> heads in ignorance...
>
> In short, will the generator "see" the load based on VA, and thus
> be pretty limited, or will it "see" the wattage?
>
> And... if it's the VA figure, then does it waste all that extra fuel
> making up for the power factor? If so, I'm actually better off using
> incandescants than CFs.... (or close enough)
>
> Enquiring minds want to know...
>
> Thanks

Ecnerwal

2005-08-21, 11:21 pm

If you're THAT worried about the CF PF, you could whip out your KAW and
figure out what size capacitor makes the PF pretty nearly 1.0, and then
wire one of those into each lamp circuit after the switch (don't want to
overcompensate). Select capacitors with appropriate ratings for
experimentation, please - nothing like hooking up a polarized capacitor
to AC for getting your attention Really Fast.

Hmm, I wonder how soon the boys at OutBack might whip up a handy offgrid
version of the massive PF auto-correcting switching capacitor banks that
some large power users have? Might be worth it on some systems if it
wasn't too expensive....

--
Cats, coffee, chocolate...vices to live by

Solar Flare

2005-08-21, 11:21 pm

What's next? PF correction in our homes to make the home pwoer system work
less?

"Steve Spence" <sspence@green-trust.org> wrote in message
news:7S9Oe.15428$U63.11294@fe12.lga...[color=darkred]
> it's va * pf, and CF's are still the better deal.
>
> Steve Spence
> Dir., Green Trust, http://www.green-trust.org
> Contributing Editor, http://www.off-grid.net
> http://www.rebelwolf.com/essn.html
>
> danny burstein wrote:
<sspence@green-trust.org> writes:[color=darkred]
their[color=darkred]

Steve Spence

2005-08-21, 11:21 pm

well, you could pick items with a number closer to 1, but I don't worry
about it. I try to run as much as I can on DC.

Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Solar Flare wrote:
> What's next? PF correction in our homes to make the home pwoer system work
> less?
>
> "Steve Spence" <sspence@green-trust.org> wrote in message
> news:7S9Oe.15428$U63.11294@fe12.lga...
>
>
> <sspence@green-trust.org> writes:
>
>
> their
>
>
>
>

Steve Spence

2005-08-21, 11:21 pm

I'm not that concerned.

Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Ecnerwal wrote:
> If you're THAT worried about the CF PF, you could whip out your KAW and
> figure out what size capacitor makes the PF pretty nearly 1.0, and then
> wire one of those into each lamp circuit after the switch (don't want to
> overcompensate). Select capacitors with appropriate ratings for
> experimentation, please - nothing like hooking up a polarized capacitor
> to AC for getting your attention Really Fast.
>
> Hmm, I wonder how soon the boys at OutBack might whip up a handy offgrid
> version of the massive PF auto-correcting switching capacitor banks that
> some large power users have? Might be worth it on some systems if it
> wasn't too expensive....
>

Jim Baber

2005-08-21, 11:21 pm

Jim Baber replys:

By golly this is the first time I have seen anyone let alone two
individuals bring up that rather esoteric subject of power factors.
They are both right on a very correct point, CFL's are terrible as far
as power factor is concerned. So are regular flourescents and induction
motors. These guys have impressed me with their comments on other
points before.

First a response to Danny, my home is on the grid, but I am a net
exporter of power much of the time for example since the last true up
with my power company I have averaged earning a $2.37 credit each day
for the 66 days since true up. I feel this is particularly interesting
because of those 66 days 36 were in excess of 100 deg. F

Back to the point of power factor, I am using power factor correction
capacitors on my entire house, so I have not been too concerned with
individual problem areas. Does this make a difference, yes!! In the
1st year I had my solar system on line, at true up I owed PG&E $475.
The 2nd year on the solar system after installing the correction
capacitance's, I ended up with a $450 credit from my utility. (which
they kept per the $%& service agreement)

Even so, I was happy with all of this since the year preceding my solar
systems startup I had paid PG&E a total of $5,300 so it was a he** of an
improvement. Having been an Electro-Mechanical Engineer long ago in
1961, I had messed around with power factor correction in regards to
mainframe computer power supply transformers for National Cash Register,
so I was familiar with power factors and the use of offsetting
capacitance's, and I wondered if power factor was hurting me at home.

I bought myself a good meter, an Extech 382065. (over $800) This is a
true RMS clampon meter with recording and direct read of power factor.
My power factor before correction averaged (24 hours) a .78 power factor
on a 101 degree day, and after correction it averaged a .97 power factor
on a slightly hotter 102 degree day. This was in June of 2004. I have
tried to tell people how important this can be, but no one listens
except the one guy in Florida who sold me the capacitors.

The power correction savings applies to all my power whether it is
coming from the grid or my solar arrays. I asked SMA specifically, if
the power factor correction would damage my Sunny Boy inverters, and I
got the answer that it wouldn't be detrimental to the inverters and they
were impressed that I had considered this. My total power consumption
(grid and PV) is down by about 6,000 kWhs this true up year without any
other lifestyle or equipment changes for the year since I installed the
correction capacitors. They came packaged in a sealed NEMA 4 waterproof
box with all the mounting hardware included. I don't recall the exact
price, but it was in the vicinity of $300, and I installed them in less
than 30 minutes.

Steve Spence wrote:

> yep, I'm looking at my 14 watt CF, and my Kill-A-Watt is reporting a
> pf of .57
>
>
> Steve Spence
> Dir., Green Trust, http://www.green-trust.org
> Contributing Editor, http://www.off-grid.net
> http://www.rebelwolf.com/essn.html
>
> danny burstein wrote:
>
>
>
>

Jim Baber

2005-08-22, 1:21 am

danny burstein wrote:

>In <Im8Oe.15417$U63.11644@fe12.lga> Steve Spence <sspence@green-trust.org> writes:
>
>
>
>
>you wouldn't know how this related to use with a portable generator,
>offhand, would you?
>
>I tried asking the question of a couple of reasonably clueful generator
>sales reps and they knew what I was talking about, but all scratched their
>heads in ignorance...
>
>In short, will the generator "see" the load based on VA, and thus
>be pretty limited, or will it "see" the wattage?
>
>And... if it's the VA figure, then does it waste all that extra fuel
>making up for the power factor? If so, I'm actually better off using
>incandescants than CFs.... (or close enough)
>
>
Jim's comment:
So you think you would be? That 47% (1 - .57) lost because of the
poor CFL power factor still resulted in a net bulb wattage of 14 Watts
didn't it? I suspect if you corrected the power factor of .57, you
would see a new total wattage of somewhere around 6.6 Watts for the
corrected circuit, and, please remember you pay your utility for the
Watts you use not VA.

I am quite sure that if you ask your utility if they charge you for
a poor power factor, they will tell you they do not charge you, despite
the fact that the agreements most users sign with the utilities, give
those utilities the right to charge the users to compensate for power
factors poorer than .85. The utilities have been quite happy in the
past to charge for that 15% (or more) of the total billed wattage that
this expected industry wide average standard power factor of .85
represented. Even though the poor power factor can be reduced quite
easily and relatively cheaply with local capacitors at the home between
the meter and the household loads.

At least that is what my investigations and the empirical numbers
and the billings for my entire house seem to imply over 2 adjacent years
usage. See my recent message in this thread.

>Enquiring minds want to know...
>
>Thanks
>
>

Solar Flare

2005-08-22, 2:21 am

That always sounds like a good idea but what do you do for backup? Have a
battery charger handy?

"Steve Spence" <sspence@green-trust.org> wrote in message
news:NaaOe.15431$U63.11630@fe12.lga...[color=darkred]
> well, you could pick items with a number closer to 1, but I don't worry
> about it. I try to run as much as I can on DC.
>
>
> Steve Spence
> Dir., Green Trust, http://www.green-trust.org
> Contributing Editor, http://www.off-grid.net
> http://www.rebelwolf.com/essn.html
>
> Solar Flare wrote:
work[color=darkred]
pf[color=darkred]

Solar Flare

2005-08-22, 2:21 am

Very interesting stuff. Reduce the VA draw on your home and up your meter
feedback watthours.

"Jim Baber" <jim@baber.org> wrote in message
news:-pKdnSgGF7pKrpTeRVn-pQ@comcast.com...
> Jim Baber replys:
>
> By golly this is the first time I have seen anyone let alone two
> individuals bring up that rather esoteric subject of power factors.
> They are both right on a very correct point, CFL's are terrible as far
> as power factor is concerned. So are regular flourescents and induction
> motors. These guys have impressed me with their comments on other
> points before.
>
> First a response to Danny, my home is on the grid, but I am a net
> exporter of power much of the time for example since the last true up
> with my power company I have averaged earning a $2.37 credit each day
> for the 66 days since true up. I feel this is particularly interesting
> because of those 66 days 36 were in excess of 100 deg. F
>
> Back to the point of power factor, I am using power factor correction
> capacitors on my entire house, so I have not been too concerned with
> individual problem areas. Does this make a difference, yes!! In the
> 1st year I had my solar system on line, at true up I owed PG&E $475.
> The 2nd year on the solar system after installing the correction
> capacitance's, I ended up with a $450 credit from my utility. (which
> they kept per the $%& service agreement)
>
> Even so, I was happy with all of this since the year preceding my solar
> systems startup I had paid PG&E a total of $5,300 so it was a he** of an
> improvement. Having been an Electro-Mechanical Engineer long ago in
> 1961, I had messed around with power factor correction in regards to
> mainframe computer power supply transformers for National Cash Register,
> so I was familiar with power factors and the use of offsetting
> capacitance's, and I wondered if power factor was hurting me at home.
>
> I bought myself a good meter, an Extech 382065. (over $800) This is a
> true RMS clampon meter with recording and direct read of power factor.
> My power factor before correction averaged (24 hours) a .78 power factor
> on a 101 degree day, and after correction it averaged a .97 power factor
> on a slightly hotter 102 degree day. This was in June of 2004. I have
> tried to tell people how important this can be, but no one listens
> except the one guy in Florida who sold me the capacitors.
>
> The power correction savings applies to all my power whether it is
> coming from the grid or my solar arrays. I asked SMA specifically, if
> the power factor correction would damage my Sunny Boy inverters, and I
> got the answer that it wouldn't be detrimental to the inverters and they
> were impressed that I had considered this. My total power consumption
> (grid and PV) is down by about 6,000 kWhs this true up year without any
> other lifestyle or equipment changes for the year since I installed the
> correction capacitors. They came packaged in a sealed NEMA 4 waterproof
> box with all the mounting hardware included. I don't recall the exact
> price, but it was in the vicinity of $300, and I installed them in less
> than 30 minutes.
>
>
>
> Steve Spence wrote:
>
>

Nick Hull

2005-08-22, 8:21 am

In article <deb8pq$9bo$1@reader2.panix.com>,
danny burstein <dannyb@panix.com> wrote:

> In short, will the generator "see" the load based on VA, and thus
> be pretty limited, or will it "see" the wattage?
>
> And... if it's the VA figure, then does it waste all that extra fuel
> making up for the power factor? If so, I'm actually better off using
> incandescants than CFs.... (or close enough)

In short, the motor sees the watts and the alternator sees the VA ;)

--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/

Steve Spence

2005-08-22, 9:21 am

solar, wind, and a 40 amp veggie fueled engine driven charger.

I'm off-grid.

Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Solar Flare wrote:
> That always sounds like a good idea but what do you do for backup? Have a
> battery charger handy?
>
> "Steve Spence" <sspence@green-trust.org> wrote in message
> news:NaaOe.15431$U63.11630@fe12.lga...
>
>
> work
>
>
> pf
>
>
>

nicksanspam@ece.villanova.edu

2005-08-22, 9:21 am

Ecnerwal <LawrenceSMITH@SOuthernVERmont.NyET> wrote:

>If you're THAT worried about the CF PF, you could whip out your KAW and
>figure out what size capacitor makes the PF pretty nearly 1.0, and then
>wire one of those into each lamp circuit after the switch...

The KAW said 14 watts at 0.57 PF, inductive? So what's the capacitor size,
and will it shorten the switch life if it's wired in parallel with the CF?

Nick

nicksanspam@ece.villanova.edu

2005-08-22, 10:21 am

Jim Baber <jim@baber.org> wrote:

>Back to the point of power factor, I am using power factor correction
>capacitors on my entire house, so I have not been too concerned with
>individual problem areas. Does this make a difference, yes!! In the
>1st year I had my solar system on line, at true up I owed PG&E $475.
>The 2nd year on the solar system after installing the correction
>capacitance's, I ended up with a $450 credit from my utility. (which
>they kept per the $%& service agreement)

I'm surprised the caps made such a big difference. Was the debit vs
credit from real energy savings in the house wiring, or more sun and
PV output, or PF credits and penalties built into the agreement?

Nick

nicksanspam@ece.villanova.edu

2005-08-22, 10:21 am

Jim Baber <jim@baber.org> wrote:

>...That 47% (1 - .57) lost because of the poor CFL power factor still
>resulted in a net bulb wattage of 14 Watts didn't it?

The KAW read 14 watts of REAL power.

>I suspect if you corrected the power factor of .57, you would see a new
>total wattage of somewhere around 6.6 Watts for the corrected circuit...

I think he might still see 14 watts of real power, but the house wiring
might only dissipate an additional 0.02x14 = 0.28 vs 0.56 watts.

Nick

Jim Baber

2005-08-22, 1:21 pm

nicksanspam@ece.villanova.edu wrote:

>Jim Baber <jim@baber.org> wrote:
>
>
>I'm surprised the caps made such a big difference.
>
>
So was I, I had figured that the vendor's suggested 8 - 12% savings were
BS, but with a combined (Solar PV production + PG&E Purchases) annual
usage of 25,990 kWh, I was really willing to spend the $300 for the
capacitors to try them. The second year the combined usage was 19,860 kWh.

>Was the debit vs credit from real energy savings in the house wiring?
>
>
I would have to say, most was real savings I believe, because of the
change in the kWh, but I have to admit I have not compared the climatic
conditions between the two years (this would affect the AC loads). This
year (the 3rd will tell) the extreme heat we've had (an all-time record
was set) should be more telling. So far I've stayed over $150 ahead of
PG&E in the 67 days since true up (beginning of my annual power bill).

>More sun and PV output?
>
>
The higher temperatures hurt Solar output this year so far, but the
solar performance in the previous 2 years was very similar in each year
with about 1 % more output in the 1st year.

>PF credits and penalties built into the agreement?
>
>
The only credits allowed are for commercial accounts that show very high
PFs and have specific credit agreements for that performance. The only
penalties are for commercial users which I am not. But even so by
PG&E's admission they aren't exercised unless the user is considerably
less than a .85 PF and is a MAJOR kWh user, and they wouldn't say how
much less or how MAJOR a user.

Loren Amelang

2005-08-22, 5:21 pm

On Mon, 22 Aug 2005 09:05:35 -0700, Jim Baber <jim@baber.org> wrote:

....[color=darkred]
>The only credits allowed are for commercial accounts that show very high
>PFs and have specific credit agreements for that performance. The only
>penalties are for commercial users which I am not. But even so by
>PG&E's admission they aren't exercised unless the user is considerably
>less than a .85 PF and is a MAJOR kWh user, and they wouldn't say how
>much less or how MAJOR a user.

Jim, what kind of inverter does your system have? I once got pretty
deeply into investigating PF in my off-grid system, and concluded that
for my Trace SW4024, with 90+ pounds of iron inside, it made little
difference in the amount of DC consumed at the input.

As you noted, utilities are only concerned about power factor for
large loads, where the extra cost of capability to transmit the
reflected power, and the heat load it adds to their generating and
transmission equipment, becomes significant. Except for what is lost
as heat, the reflected power itself comes back to them and does not
increase their fuel cost.

Likewise, in my heavy transformer based Trace, the reflected power
appears to return to the inductance of the inverter with no net impact
on the DC input side. My measurements of several (admittedly lower
Wattage) inverters that do not use a heavy transformer on the 60 Hz
side showed the opposite - they were unable to absorb the reflected
power for re-use, instead dissipating it as heat. Adding PF correction
capacitors reduced their DC input load significantly, and made them
run cooler and sound much happier.

I'd be very curious to hear the weight of your inverter!

Loren

Jim Baber

2005-08-22, 9:21 pm

Loren Amelang wrote:

>On Mon, 22 Aug 2005 09:05:35 -0700, Jim Baber <jim@baber.org> wrote:
>
>
>
>....
>
>
>
>Jim, what kind of inverter does your system have? ..........
>
>
I have 4 SMA Sunny Boy SWR 2500U inverters.

> <>..................I once got pretty deeply into investigating PF in
> my off-grid system, and
> concluded that for my Trace SW4024, with 90+ pounds of iron inside, it
> made little
> difference in the amount of DC consumed at the input.
>
> As you noted, utilities are only concerned about power factor for
> large loads, where the extra cost of capability to transmit the
> reflected power, and the heat load it adds to their generating and
> transmission equipment, becomes significant. Except for what is lost
> as heat, the reflected power itself comes back to them and does not
> increase their fuel cost.
>
> Likewise, in my heavy transformer based Trace, the reflected power
> appears to return to the inductance of the inverter with no net impact
> on the DC input side. My measurements of several (admittedly lower
> Wattage) inverters that do not use a heavy transformer on the 60 Hz
> side showed the opposite - they were unable to absorb the reflected
> power for re-use, instead dissipating it as heat. Adding PF correction
> capacitors reduced their DC input load significantly, and made them
> run cooler and sound much happier.
>
> I'd be very curious to hear the weight of your inverter!

<>They each weigh 70 pounds.

> <>Loren

Solar Flare

2005-08-22, 9:21 pm

Again. What do you do for backup if you run items on your DC system? Are
your DC components totally expendable? Have you faced that problem yet in
your conquests?

"Steve Spence" <sspence@green-trust.org> wrote in message
news:%FiOe.4107$_7.3968@fe08.lga...[color=darkred]
> solar, wind, and a 40 amp veggie fueled engine driven charger.
>
> I'm off-grid.
>
> Steve Spence
> Dir., Green Trust, http://www.green-trust.org
> Contributing Editor, http://www.off-grid.net
> http://www.rebelwolf.com/essn.html
>
> Solar Flare wrote:
a[color=darkred]
generator[color=darkred]

Solar Flare

2005-08-22, 9:21 pm

Exactly. Power (watts as some call it) cannot be "bent" or improved. It is
the actual output of the device.

VAs however can be "bent" improved or relieved by taking PF correction
seriously. This is the apparent power taken from the generating device to
achieve the "wattage" required. The PF is the rating of the effective usage
or non-wastage.

Improving power factor should relieve your equipment of a big wasted burden
on your batteries and inverter.

Good enough typage?

<nicksanspam@ece.villanova.edu> wrote in message
news:decgm6$174@acadia.ece.villanova.edu...
> Jim Baber <jim@baber.org> wrote:
>
>
> The KAW read 14 watts of REAL power.
>
>
> I think he might still see 14 watts of real power, but the house wiring
> might only dissipate an additional 0.02x14 = 0.28 vs 0.56 watts.
>
> Nick
>

Roger_Nickel

2005-08-23, 4:21 am

danny burstein wrote:
> In <Im8Oe.15417$U63.11644@fe12.lga> Steve Spence <sspence@green-trust.org> writes:
>
>
>
>
> you wouldn't know how this related to use with a portable generator,
> offhand, would you?
>
> I tried asking the question of a couple of reasonably clueful generator
> sales reps and they knew what I was talking about, but all scratched their
> heads in ignorance...
>
> In short, will the generator "see" the load based on VA, and thus
> be pretty limited, or will it "see" the wattage?
>
> And... if it's the VA figure, then does it waste all that extra fuel
> making up for the power factor? If so, I'm actually better off using
> incandescants than CFs.... (or close enough)
>
> Enquiring minds want to know...
>
> Thanks
Copper losses in the generator depend on current in the windings;
which does not depend on power factor. There will be other losses,
e.g in the regulator circuit and field windings which do depend on
VA output. CFL's and computers both get their power from full wave
rectifiers on the mains. This means that they draw their power as
a series of short pulses near the peak of the voltage waveform and
the resulting non-sinusoidal current waveform ruins the power
factor and also introduces high order harmonic currents into the
generator windings resulting in copper losses and somewhat reduced
efficiency. As to the exact energy loss; from here the answer has
to be "it depends---".

Roger_Nickel

2005-08-23, 4:21 am

Jim Baber wrote:

> Jim's comment:
> So you think you would be? That 47% (1 - .57) lost because of the
> poor CFL power factor still resulted in a net bulb wattage of 14 Watts
> didn't it? I suspect if you corrected the power factor of .57, you
> would see a new total wattage of somewhere around 6.6 Watts for the
> corrected circuit, and, please remember you pay your utility for the
> Watts you use not VA.
> I am quite sure that if you ask your utility if they charge you for a
> poor power factor, they will tell you they do not charge you, despite
> the fact that the agreements most users sign with the utilities, give
> those utilities the right to charge the users to compensate for power
> factors poorer than .85. The utilities have been quite happy in the
> past to charge for that 15% (or more) of the total billed wattage that
> this expected industry wide average standard power factor of .85
> represented. Even though the poor power factor can be reduced quite
> easily and relatively cheaply with local capacitors at the home between
> the meter and the household loads.
>
I think that traditional Faraday disc meters use both voltage and
current sense windings to do a real-time V*A calculation which
inherently accounts for power factor but harmonic distortion of
the current or voltage waveforms could cause a problem with
measurement accuracy. Industrial customers are likely to pay a
line charge based on peak current demand and it is in their own
interests to use power factor correction.

Vaughn

2005-08-23, 7:21 am

"Roger_Nickel" <rnickel@x.co.nz> wrote in message
news:430ac7f0$1@news2.actrix.gen.nz...
> CFL's and computers both get their power from full wave rectifiers on the
> mains. This means that they draw their power as a series of short pulses near
> the peak of the voltage waveform and the resulting non-sinusoidal current
> waveform ruins the power factor and also introduces high order harmonic
> currents into the generator windings resulting in copper losses and somewhat
> reduced efficiency.

I will sign on to all of the above except for the part about the full wave
bridge. Power factor and supply-side harmonics have little to do with a full
wave rectifier (a half wave rectifier is rare and another story) and everything
to do with switching power supplies. A switching power supply operates exactly
like an early automotive voltage regulator. You have a switch between the line
and the load, and that switch is fully on or fully off at any given moment.
Because the regulator is normally taking an input that is well over 100 volts
and supplying a load that is less than 20 volts, you can easily imagine that the
switch will be "on" for only the briefest period of time. The more current that
you draw from the load, the more often the switch will be on. The switch may be
"on" several times in any given cycle and it is up to the generator and/or power
distribution system to sort out the resulting mess.

Vaughn

>As to the exact energy loss; from here the answer has to be "it depends---".

nicksanspam@ece.villanova.edu

2005-08-23, 9:21 am

Roger_Nickel <rnickel@x.co.nz> wrote:

>Copper losses in the generator depend on current in the windings;
>which does not depend on power factor.

Wrong.

Nick

Loren Amelang

2005-08-23, 4:21 pm

On Mon, 22 Aug 2005 16:21:31 -0700, Jim Baber <jim@baber.org> wrote:

>Loren Amelang wrote:
>
>I have 4 SMA Sunny Boy SWR 2500U inverters.
>
><>They each weigh 70 pounds.

Hmmm... According to Fig. 2.2 in
<http://www.sma-america.com/ftp/SB25...Tech%20Desc.pdf>
it looks like much of that 70 pounds is a line-frequency transformer
across the inverter output. And ~70 pounds for 2500 Watts is
proportionately more iron than my ~90 pounds for 4000 Watts. If you
really are seeing a big improvement from PF correction, there must be
more to this than just line-frequency iron.

The obvious difference is that my input is paralleled with a big
battery bank at 24 V, while yours appears to be panel direct at
several hundred Volts. And your Sunny Boys are doing some kind of
MPPT, which might be confused by a poor power factor on the output
side.

Another difference is that presumably your inverters are running at a
significant proportion of their capacity for most of the day, while my
PF tests were made with single isolated loads far lower than 4 KW. So
in proportion to the actual reflected power during the test, I
probably had far more iron to absorb it.

It would be interesting to watch your Vpv and Ipv versus Pac while
switching your PF caps in and out - might reveal whether the effect is
real, and whether MPPT has something to do with it.

Loren

daestrom

2005-08-23, 6:21 pm

"Loren Amelang" <loren@pacific.net> wrote in message
news:lormg1l4pneqpmust8cj5687ivkjmu36dm@4ax.com...
> On Mon, 22 Aug 2005 16:21:31 -0700, Jim Baber <jim@baber.org> wrote:
>
>
> Hmmm... According to Fig. 2.2 in
> <http://www.sma-america.com/ftp/SB25...Tech%20Desc.pdf>
> it looks like much of that 70 pounds is a line-frequency transformer
> across the inverter output. And ~70 pounds for 2500 Watts is
> proportionately more iron than my ~90 pounds for 4000 Watts. If you
> really are seeing a big improvement from PF correction, there must be
> more to this than just line-frequency iron.
>
> The obvious difference is that my input is paralleled with a big
> battery bank at 24 V, while yours appears to be panel direct at
> several hundred Volts. And your Sunny Boys are doing some kind of
> MPPT, which might be confused by a poor power factor on the output
> side.
>

Now, see this is what confuses me. Jim is running a grid-tie setup, so the
load's pf is *not* what the inverter is feeding. The supply impedance of
any normal sized service entrance is very low and able to feed a wide range
of load pf with no problem. And the utility certainly doesn't much care
about any single residential service's pf. They could feed a 200A service
at 0.1 pf just as easily as one at 1.0 pf. It just doesn't make that much
difference to your average substation what one individual house's pf is.
All that Jim's inverter 'sees' is a sinusoidal AC supply, and a very, very
low source impedance to feed back into.

I presume that Jim's system runs at the MPPT point for his panels most of
the day. I would be most interested in the inverter output stage and how
the caps have changed the inverter output. I suspect his caps added to the
service panel are effectively changing the output stage of the inverter and
somehow affecting it's metering or actual output.

Simple grid-tie inverters just trigger thyristor's in sync with the grid
supply. So the applied voltage is pretty much a square wave. But the low
impedance of the grid supply, coupled with the output transformer limit the
voltage rise. The result is the inverter's output current is pretty high in
harmonics itself. This harmonic content may prevent the utility meter from
registering the full power of the inverter output. Jim's caps would smooth
out the inverter's very non-linear current supply and perhaps improve the
overall readings.

>
> It would be interesting to watch your Vpv and Ipv versus Pac while
> switching your PF caps in and out - might reveal whether the effect is
> real, and whether MPPT has something to do with it.
>

I suspect that if Jim turned off *all* the loads in the house, and then
watched inverter output / utility meter while switching just the cap bank
in/out, it would make a difference. Not the house load's pf (or correction
of same).

daestrom

Jim Baber

2005-08-23, 6:21 pm

Jim's response to Loren
I appreciate your interest, and that might account for it, but see
my comment to your MPPT question
Loren Amelang wrote:

>On Mon, 22 Aug 2005 16:21:31 -0700, Jim Baber <jim@baber.org> wrote:
>
>
>
>
>Hmmm... According to Fig. 2.2 in
><http://www.sma-america.com/ftp/SB25...Tech%20Desc.pdf>
>it looks like much of that 70 pounds is a line-frequency transformer
>across the inverter output. And ~70 pounds for 2500 Watts is
>proportionately more iron than my ~90 pounds for 4000 Watts. If you
>really are seeing a big improvement from PF correction, there must be
>more to this than just line-frequency iron.
>
>The obvious difference is that my input is paralleled with a big
>battery bank at 24 V, while yours appears to be panel direct at
>several hundred Volts.
>
True, right now I just checked all the Pv at the inverters @ 12:30 today at
343 , 340 , 339, and 343 VDC. and they were outputting 7728 Watts with
5043 Watts being exported to the grid, the balance running the house's
current loads (computers refrigerator wall worts fans lights etc.).

>And your Sunny Boys are doing some kind of
>MPPT, which might be confused by a poor power factor on the output
>side.
>
>Another difference is that presumably your inverters are running at a
>significant proportion of their capacity for most of the day, while my
>PF tests were made with single isolated loads far lower than 4 KW. So
>in proportion to the actual reflected power during the test, I
>probably had far more iron to absorb it.
>
>It would be interesting to watch your Vpv and Ipv versus Pac while
>switching your PF caps in and out - might reveal whether the effect is
>real, and whether MPPT has something to do with it.
>
>Loren
>
It would, but the caps are not on switches and in fact are piggy backed
on the
same dual 50A 240V breakers as the main AC unit, since:
1. The AC is the biggest single pf culprit.
2. The AC had a sufficient amperage capacity. (The caps do not load the
breaker since not the same phasing as the AC load so this does seem
to work OK, in fact the circuit breakers appears cooler to the
touch now.)
3. I didn't have any more dual breaker slots in my 200A service breaker
panel.
Therefore I can't use the breaker as a switch without turning
off the AC, which
would distort the very picture we are curious about without a
major load.

Solar Flare

2005-08-23, 7:21 pm

The I squared R losses are also power or "wattage" inside the windings and
not VAs. Not related to the pF of the load at all. It's the power factor of
the copper in the windings (and iron cores) that counts.

"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:rSLOe.29811$Hx4.27336@twister.nyroc.rr.com...
>
> <nicksanspam@ece.villanova.edu> wrote in message
> news:def182$2vq@acadia.ece.villanova.edu...
>
> No, actually he is correct. The copper losses in a generator (also called
> the I^2R losses) are a function of the current only. Pf does not enter
into
> it at all. If the current is not sinusoidal (such as rich in harmonics),
> then the losses are *still* just I^2R in the copper. But figuring out the
> true RMS current passing through the windings is a bit tougher.
>
> daestrom
>
>

nicksanspam@ece.villanova.edu

2005-08-23, 7:21 pm

daestrom <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:

[color=darkred]
>No, actually he is correct.

Wrong.

Nick

Dave Hinz

2005-08-23, 7:21 pm

On 23 Aug 2005 17:23:49 -0400, nicksanspam@ece.villanova.edu <nicksanspam@ece.villanova.edu> wrote:
> daestrom <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>
>
>
> Wrong.

Can you be less vague, or is this some sort of Monty Python thing?

Solar Flare

2005-08-23, 7:21 pm

I believe that the inverters are rated in Watts as a mistake. Any power
source is usually rated in VA or just plain current (amps) as the example of
the genertaor you previously posted.

If you have a 1000W load that draws 2000va (50% pf) then 2000va is the work
the inverter has to supply due to the current draw. If you pf correct the
load the va goes down to 1000va and the inverter/grid-tie can now supply
more va back into the grid.

Seems the manufacturers all specify so many watts capacity and it probably
isn't a true rating.

"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:53MOe.29813$Hx4.6454@twister.nyroc.rr.com...
>
> "Loren Amelang" <loren@pacific.net> wrote in message
> news:lormg1l4pneqpmust8cj5687ivkjmu36dm@4ax.com...
correction[color=darkred]
>
> Now, see this is what confuses me. Jim is running a grid-tie setup, so
the
> load's pf is *not* what the inverter is feeding. The supply impedance of
> any normal sized service entrance is very low and able to feed a wide
range
> of load pf with no problem. And the utility certainly doesn't much care
> about any single residential service's pf. They could feed a 200A service
> at 0.1 pf just as easily as one at 1.0 pf. It just doesn't make that much
> difference to your average substation what one individual house's pf is.
> All that Jim's inverter 'sees' is a sinusoidal AC supply, and a very, very
> low source impedance to feed back into.
>
> I presume that Jim's system runs at the MPPT point for his panels most of
> the day. I would be most interested in the inverter output stage and how
> the caps have changed the inverter output. I suspect his caps added to
the
> service panel are effectively changing the output stage of the inverter
and
> somehow affecting it's metering or actual output.
>
> Simple grid-tie inverters just trigger thyristor's in sync with the grid
> supply. So the applied voltage is pretty much a square wave. But the low
> impedance of the grid supply, coupled with the output transformer limit
the
> voltage rise. The result is the inverter's output current is pretty high
in
> harmonics itself. This harmonic content may prevent the utility meter
from
> registering the full power of the inverter output. Jim's caps would
smooth
> out the inverter's very non-linear current supply and perhaps improve the
> overall readings.
>
>
> I suspect that if Jim turned off *all* the loads in the house, and then
> watched inverter output / utility meter while switching just the cap bank
> in/out, it would make a difference. Not the house load's pf (or
correction
> of same).
>
> daestrom
>
>

Arnold Walker

2005-08-23, 7:21 pm

Do you use radio transmitters in the area....touch style electronic switch
will trigger off the RF.
Remember ,years ago ....my first adventure with packet radio.
You finally had the computer interfaced to the radio and fired up for a
radio transmission.
The appartment ,I was in had ,was100% electronic touch on all switches thru
out the appartment.
Before you even had a "handshake" on the other packet point.The lights were
strobing like a disco.
And didn't quit until you killed the transmitter.
That may not be a problem since now ,trunked 800(later know as cell phone)
among other fregs. are maybe
10% of the power they used to be.

"Jim Baber" <jim@baber.org> wrote in message
news:ZoidnXH5NaQHfZXeRVn-oA@comcast.com...
> Jim replys:
>
> Too_Many_Tools wrote:
>
> Yes, these are electronic switches and they do require a very small
> sensing circuit to tell when you touch them.
>
> I am a firm believer in using CFL (Compact Fluorescent Light) wherever
> you can and there are good variable CFL bulbs that will save a
> considerable amount of money in the long term over the usual
> incandescent bulbs, BUT, these are going to originally cost considerably
> more than either incandescent or non variable CFL lights.
>
> I have had good luck with them in my dining room fixture, and
> particularly good luck in my ceiling fan's light fixtures where the fan
> control came with a light dimmer function. These dimmers were
> frequently accidentally used and when I had regular CFL bulbs in the 3
> fan fixtures I have, they failed frequently. However once I put the
> dimmable CFL bulbs in the fan fixtures, the problems went away and I
> dropped each bulb wattage from 100 W. to 23 W. (9 bulbs total) By the
> way, the CFL bulbs do last a lot better than incandescent bulbs in the
> fans because they don't seem to be affected as much by the vibrations of
> the fans.
>
> I also have used these "variable CFL" bulbs in a bedside lamp that has
> the kind of touch sensitive 4 way switch you mentioned at first quite
> successfully. I also have one in a X-10 lamp module controlled light
> that seems to function OK as far as dimming, at least whenever the
> module decides to work, but the X-10 module itself is being it's usual
> PIA self.
>
> Hope this helps.
>
>

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Roger_Nickel

2005-08-24, 4:21 am

Vaughn wrote:
> "Roger_Nickel" <rnickel@x.co.nz> wrote in message
> news:430ac7f0$1@news2.actrix.gen.nz...
>

>
> I will sign on to all of the above except for the part about the full wave
> bridge. Power factor and supply-side harmonics have little to do with a full
> wave rectifier (a half wave rectifier is rare and another story) and everything
> to do with switching power supplies. A switching power supply operates exactly
> like an early automotive voltage regulator. You have a switch between the line
> and the load, and that switch is fully on or fully off at any given moment.
> Because the regulator is normally taking an input that is well over 100 volts
> and supplying a load that is less than 20 volts, you can easily imagine that the
> switch will be "on" for only the briefest period of time. The more current that
> you draw from the load, the more often the switch will be on. The switch may be
> "on" several times in any given cycle and it is up to the generator and/or power
> distribution system to sort out the resulting mess.
>
> Vaughn

When I wrote the OP I had in mind the design of power supply in
which the switch mode regulator runs off a reservoir capacitor
which is charged to peak mains voltage via a full wave bridge
across the mains. This arrangement certainly does result in high
peak currents syncronised with rectified voltage peaks and in
harmonic distortion of the mains current waveform but it is not
current practice. Current practice is to charge the reservoir
capacitor from a boost regulator connected directly to the
rectified output of the full wave bridge. The input of the boost
regulator follows the fullwave rectified mains voltage waveform
and high freqency PWM of the boost stage allows the reservoir
capacitor to charge continuously rather than only at the peaks of
the rectified mains waveform. The PWM current components reflected
back into the mains supply are at hundreds of kilohertz, are
easily filtered and all is sweetness and light. Thanks for
prompting me to update my knowledge on this topic.

LinkBot