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| Tim Thomson 2006-01-08, 11:21 pm |
| Got into a argument at the pub the other day. LOL
According to the guy I was arguing with he says that if I am going to
use resistive heating that I should use 220vac instead of 110vac because
I will get twice the heat (BTU) for half the power reading on my metor?
I need something to print off to esplain to him how 220 works....221
whats the diff right.
| |
| SolarFlaire 2006-01-08, 11:21 pm |
| If you have 1200 watts of heat (baseboard or whatever)
this will take 10 amperes of current at 120 volts.
This will also take 5 amperes at 240 volts.
Multiplying your volts times your amperes (current)
will yield watts or the heat you will get from your
heater.
i.e.: 5 amps X 240 volts = 1200 watts
10 amps X 120 volts = 1200 watts
So your friend is correct but a little confused. Yes,
the heater will take half the amperes at 240 volts but
the power (watts) will be the same in either case and
that is what your meter will see either method.
Now for the clincher. At 120 volts your heating will
take twice the current (amps) and that takes twice the
copper conductors (cross section) to get it there. Much
heavier wire needs to be run and that costs bucks.
Good luck
"Tim Thomson" <thomsontim@shaw.ca> wrote in message
news:43C1CBC9.69C446DE@shaw.ca...
> Got into a argument at the pub the other day. LOL
> According to the guy I was arguing with he says that
if I am going to
> use resistive heating that I should use 220vac
instead of 110vac because
> I will get twice the heat (BTU) for half the power
reading on my metor?
> I need something to print off to esplain to him how
220 works....221
> whats the diff right.
>
| |
| Drums 2006-01-08, 11:21 pm |
| Nonsense. What he was trying to say it's the it's more efficient.
Half the power reading your meter? I don't think so Tim. ;o)
"Tim Thomson" <thomsontim@shaw.ca> wrote in message
news:43C1CBC9.69C446DE@shaw.ca...
> Got into a argument at the pub the other day. LOL
> According to the guy I was arguing with he says that if I am going to
> use resistive heating that I should use 220vac instead of 110vac because
> I will get twice the heat (BTU) for half the power reading on my metor?
> I need something to print off to esplain to him how 220 works....221
> whats the diff right.
>
| |
| Drums 2006-01-08, 11:21 pm |
| Well it's actually 240, not 220.
"Drums" <tgiorgi1@REMOVEnycap.rr.com> wrote in message
news:O8kwf.77952$XC4.54112@twister.nyroc.rr.com...
> Nonsense. What he was trying to say it's the it's more efficient.
> Half the power reading your meter? I don't think so Tim. ;o)
>
>
> "Tim Thomson" <thomsontim@shaw.ca> wrote in message
> news:43C1CBC9.69C446DE@shaw.ca...
>
>
| |
| Rick Frazier 2006-01-09, 12:21 am |
| In the simplest look, the amount of BTU you get from a given heater
should be the same, given the watts of electricity consumed. However,
that said, you should also bear in mind that some power meters don't
handle high current on one side of the 240 volt line very well. This is
primarily due to the electric company providing and metering at 240
volts. I've seen a few that will meter a 10 ampere load on 120 volts
(one side only) as if it were a 10 ampere load for the entire 240 volt
service, unless there is a corresponding load on the other side of the
line. Not all meters have this problem, but there are some out there
that still do. It's not exactly in the best interests of the power
company to replace these meters, as they are money makers in the event
you present an unbalanced load.
Thus, if you have a single heater on one side of the line, or two
heaters on the two sides of the line (neutral being the boundary between
the two 120 volt lines) and one heater runs more than the other, the net
cost could be higher than if you were using 240 volt heaters of the same
wattage.
Another problem you can run into is load imbalance affecting the actual
voltages you see on each side of the line. In extreme
circumstances, putting a large 120 volt load on one side of the 240
volt supply will "float" the neutral, moving it considerably away from
nominal 0 volts. This can cause a lower net voltage on the heavily
loaded side and a higher net voltage on the lightly loaded side. (This
effect is especially seen in cases where "daisy chain" wiring is the
norm, and there are one or more wirenut connections that are less than
perfect.) It's not unusual for older homes to see 100 volts on a heavy
loaded side, while there is 140 volts on the lightly loaded side. This
can play havoc with all sorts of devices on the higher voltage side of
the line. Unfortunately, some "marginally wired" newer homes have as
much problem with this as older homes, because some of the wiring is
done with 4 wires in a sheath, not two separate, three wire sheaths to
different circuits. With the 4 wire sheath, there are two "hot" wires,
one neutral, and one safety ground. The assumption is that the two hot
lines will have equal currents and the net current in the neutral will
be near zero, or at least the maximum offset will be within the current
carrying capability of the neutral wire. Unfortunately, this is not
always the case, even if correctly configured. Also, if this sort of
sheathed cable is incorrectly connected (both hot wires on the same side
of the line) it can present a significant hazard if both circuits are
heavily loaded. With two separate sheathed cables, each circuit has a
dedicated hot, neutral and safety ground, each of which is connected
directly to the distribution panel and not shared with any other
circuits.
During the initial construction, the loads are supposed to be
distributed equally on both sides of the line to present as balanced a
load as possible on the 240 volt service. This limits the potential
exposure to running heavy loads on one side of the line compared to the
other. Unfortunately, not all electricians care enough to actually
balance the expected loads, and many homeowners add things like portable
120 volt space heaters that radically affect this possible balance.
Most baseboard heaters are 240 volts, while portable plug-in units tend
to be 120 volts (at least in the US).
As already mentioned by a previous poster, running wire to 240 volt
heaters is less expensive (per watt) than 120 volt heaters. If you are
considering new wiring to handle electrical heaters, you should at least
consider 240 volt ones. If, on the other hand, you are using portable
units, you should be very careful to make sure the ones you purchase
have tip sensors (and shut off when the unit is disturbed or tipped
over), and at least try to balance the loads on opposite sides of the
240 volt line so you don't end up paying even more than you normally
would for electric heat. Also, you should be aware that most baseboard
heaters run at a lower temperature (at least on a per square inch
basis), and are inherently more safe (especially when unattended by a
careful adult) than most portables, which require minimum 36" spacing
from flammable objects...
For my money, I'd use 240 volt heaters and avoid the potential problems
with balancing the 120 volt ones.
--Rick
SolarFlaire wrote:
[color=darkred]
> If you have 1200 watts of heat (baseboard or whatever)
> this will take 10 amperes of current at 120 volts.
>
> This will also take 5 amperes at 240 volts.
>
> Multiplying your volts times your amperes (current)
> will yield watts or the heat you will get from your
> heater.
>
> i.e.: 5 amps X 240 volts = 1200 watts
> 10 amps X 120 volts = 1200 watts
>
> So your friend is correct but a little confused. Yes,
> the heater will take half the amperes at 240 volts but
> the power (watts) will be the same in either case and
> that is what your meter will see either method.
>
> Now for the clincher. At 120 volts your heating will
> take twice the current (amps) and that takes twice the
> copper conductors (cross section) to get it there. Much
> heavier wire needs to be run and that costs bucks.
>
> Good luck
>
> "Tim Thomson" <thomsontim@shaw.ca> wrote in message
> news:43C1CBC9.69C446DE@shaw.ca...
> if I am going to
> instead of 110vac because
> reading on my metor?
> 220 works....221
| |
| SolarFlaire 2006-01-09, 12:21 am |
| Not in Canada you won't see a meter do that. I have
seen all the approvals.
Can you state a meter type that can do this?
To aid in your confusion, the run-of-the-mill domestic
meter has only one potential coil (240V) and two "half"
current coils, one on each leg. Yes, it's to make it
cheaper.
Yes on a severely unbalanced ***VOLTAGE*** system there
can be unfair metering. One leg will meter with it's
current against half the total voltage. If you are
loading the low voltage leg then you are getting an
error against you.
This is only can only be slight (less than about 2%)
without wires and devices burning up, or bad
connections causing same usually.
A balanced electrical system is always good as your
neutral may not be sized to handle the load the line
legs are.
Now, on some multi unit complexes there is such a thing
as a "network" meter where three phase power is
supplied and only two legs and a neutral is supplied
each unit. This can save on copper. The voltages are
now at 120 degrees to each other and the voltages would
classically be 125, 125 and 216 vac. A phase to phase
load requiring 10 amps at 216 volts would consume 2160
watts (assuming resistive) the meter would see 10amps x
120 volts in each leg and although it would appear to
add up to 2400 watts there is a 30 degree phase angle
in each leg so the meter would see 120volts x 10amps x
cos(30deg) = 1080 watts in each leg for a total of 2160
watts!
Now VA demand customers get ripped as there are
differences between arithmetic summation of va and
phasor addition of va. One favours the utility and one
favours the customer. Domestic users never have to
worry about this problem.
Hope that confuses the shit out of ya....LOL
"Rick Frazier" <rickf@rickfrazier.com> wrote in message
news:43C1D71F.EF371636@rickfrazier.com...
> In the simplest look, the amount of BTU you get from
a given heater
> should be the same, given the watts of electricity
consumed. However,
> that said, you should also bear in mind that some
power meters don't
> handle high current on one side of the 240 volt line
very well. This is
> primarily due to the electric company providing and
metering at 240
> volts. I've seen a few that will meter a 10 ampere
load on 120 volts
> (one side only) as if it were a 10 ampere load for
the entire 240 volt
> service, unless there is a corresponding load on the
other side of the
> line. Not all meters have this problem, but there
are some out there
> that still do. It's not exactly in the best
interests of the power
> company to replace these meters, as they are money
makers in the event
> you present an unbalanced load.
>
> Thus, if you have a single heater on one side of the
line, or two
> heaters on the two sides of the line (neutral being
the boundary between
> the two 120 volt lines) and one heater runs more than
the other, the net
> cost could be higher than if you were using 240 volt
heaters of the same
> wattage.
>
> Another problem you can run into is load imbalance
affecting the actual
> voltages you see on each side of the line. In
extreme
> circumstances, putting a large 120 volt load on one
side of the 240
> volt supply will "float" the neutral, moving it
considerably away from
> nominal 0 volts. This can cause a lower net voltage
on the heavily
> loaded side and a higher net voltage on the lightly
loaded side. (This
> effect is especially seen in cases where "daisy
chain" wiring is the
> norm, and there are one or more wirenut connections
that are less than
> perfect.) It's not unusual for older homes to see
100 volts on a heavy
> loaded side, while there is 140 volts on the lightly
loaded side. This
> can play havoc with all sorts of devices on the
higher voltage side of
> the line. Unfortunately, some "marginally wired"
newer homes have as
> much problem with this as older homes, because some
of the wiring is
> done with 4 wires in a sheath, not two separate,
three wire sheaths to
> different circuits. With the 4 wire sheath, there
are two "hot" wires,
> one neutral, and one safety ground. The assumption
is that the two hot
> lines will have equal currents and the net current in
the neutral will
> be near zero, or at least the maximum offset will be
within the current
> carrying capability of the neutral wire.
Unfortunately, this is not
> always the case, even if correctly configured. Also,
if this sort of
> sheathed cable is incorrectly connected (both hot
wires on the same side
> of the line) it can present a significant hazard if
both circuits are
> heavily loaded. With two separate sheathed cables,
each circuit has a
> dedicated hot, neutral and safety ground, each of
which is connected
> directly to the distribution panel and not shared
with any other
> circuits.
>
> During the initial construction, the loads are
supposed to be
> distributed equally on both sides of the line to
present as balanced a
> load as possible on the 240 volt service. This
limits the potential
> exposure to running heavy loads on one side of the
line compared to the
> other. Unfortunately, not all electricians care
enough to actually
> balance the expected loads, and many homeowners add
things like portable
> 120 volt space heaters that radically affect this
possible balance.
>
> Most baseboard heaters are 240 volts, while portable
plug-in units tend
> to be 120 volts (at least in the US).
> As already mentioned by a previous poster, running
wire to 240 volt
> heaters is less expensive (per watt) than 120 volt
heaters. If you are
> considering new wiring to handle electrical heaters,
you should at least
> consider 240 volt ones. If, on the other hand, you
are using portable
> units, you should be very careful to make sure the
ones you purchase
> have tip sensors (and shut off when the unit is
disturbed or tipped
> over), and at least try to balance the loads on
opposite sides of the
> 240 volt line so you don't end up paying even more
than you normally
> would for electric heat. Also, you should be aware
that most baseboard
> heaters run at a lower temperature (at least on a per
square inch
> basis), and are inherently more safe (especially when
unattended by a
> careful adult) than most portables, which require
minimum 36" spacing
> from flammable objects...
>
> For my money, I'd use 240 volt heaters and avoid the
potential problems
> with balancing the 120 volt ones.
>
> --Rick
>
>
> SolarFlaire wrote:
>
whatever)[color=darkred]
Yes,[color=darkred]
but[color=darkred]
and[color=darkred]
will[color=darkred]
the[color=darkred]
Much[color=darkred]
that[color=darkred]
power[color=darkred]
how[color=darkred]
>
| |
| Tim Thomson 2006-01-09, 1:21 am |
| SolarFlaire wrote:
[color=darkred]
> Not in Canada you won't see a meter do that. I have
> seen all the approvals.
>
> Can you state a meter type that can do this?
>
> To aid in your confusion, the run-of-the-mill domestic
> meter has only one potential coil (240V) and two "half"
> current coils, one on each leg. Yes, it's to make it
> cheaper.
>
> Yes on a severely unbalanced ***VOLTAGE*** system there
> can be unfair metering. One leg will meter with it's
> current against half the total voltage. If you are
> loading the low voltage leg then you are getting an
> error against you.
>
> This is only can only be slight (less than about 2%)
> without wires and devices burning up, or bad
> connections causing same usually.
>
> A balanced electrical system is always good as your
> neutral may not be sized to handle the load the line
> legs are.
>
> Now, on some multi unit complexes there is such a thing
> as a "network" meter where three phase power is
> supplied and only two legs and a neutral is supplied
> each unit. This can save on copper. The voltages are
> now at 120 degrees to each other and the voltages would
> classically be 125, 125 and 216 vac. A phase to phase
> load requiring 10 amps at 216 volts would consume 2160
> watts (assuming resistive) the meter would see 10amps x
> 120 volts in each leg and although it would appear to
> add up to 2400 watts there is a 30 degree phase angle
> in each leg so the meter would see 120volts x 10amps x
> cos(30deg) = 1080 watts in each leg for a total of 2160
> watts!
>
> Now VA demand customers get ripped as there are
> differences between arithmetic summation of va and
> phasor addition of va. One favours the utility and one
> favours the customer. Domestic users never have to
> worry about this problem.
>
> Hope that confuses the shit out of ya....LOL YA LOL
> how
| |
| Tim Thomson 2006-01-09, 1:21 am |
| Drums wrote:
[color=darkred]
> Well it's actually 240, not 220.
>
> "Drums" <tgiorgi1@REMOVEnycap.rr.com> wrote in message
> news:O8kwf.77952$XC4.54112@twister.nyroc.rr.com...
Nope it's 221
| |
|
|
Tim Thomson wrote:[color=darkred]
>
> SolarFlaire wrote:
>
I would use the "KISS" principle ....
You pay your bill in watts (actually killo watts, KW)....
so that is what is important....
An electric heater rated at 1500 watts manufactured to run at 110 volts
will produce
1500 watts of heat....
An electric heater rated at 1500 watts manufactured to run at 220 volts
will produce
1500 watts of heat....
Since you are paying for watts the cost will be the same (approximately)
If you want to get into the math remember the word "PIE"
Power (watts) = I (current, amps) * E (voltage, volts)
1500 watts = 13.6 amps * 110 volts
1500 watts = 6.8 amps * 220 volts
Since the power will be the same in both of them....if the voltage is
doubled the
current must be halved....in order to keep the power the same.....so he
is right
that the current is cut in half going from 110 to 200 but the power
(what you pay
for) is the same.....
hope this is even more confusing <grin>....have fun......sno
--
Seen it all, done it all, can't remember most of it
This tag line is generated by:
SLTG (Silly Little Tag Generator)
| |
| Drums 2006-01-09, 10:21 am |
| Not here. Nominal line is 238.
"Tim Thomson" <thomsontim@shaw.ca> wrote in message
news:43C1F0EF.182E5B79@shaw.ca...
> Drums wrote:
>
to[color=darkred]
because[color=darkred]
metor?[color=darkred]
>
> Nope it's 221
>
>
| |
| barry@sme-online.com 2006-01-09, 4:21 pm |
| Actually neither. Std is 117v rms single-phase, x2 that's ... right-
234v rms.
That std is pretty old, too.
HTH,
J
| |
|
| Sorry, your wrong if you want to be nit picky. RMS 110 is actually over 300
volts Peek to Peek. ;o)
And my line volatge is 119.00. Always has been. Lowest I have seen is 115.
<barry@sme-online.com> wrote in message
news:1136834028.594757.179250@f14g2000cwb.googlegroups.com...
> Actually neither. Std is 117v rms single-phase, x2 that's ... right-
> 234v rms.
>
> That std is pretty old, too.
>
> HTH,
> J
>
| |
| daestrom 2006-01-09, 9:21 pm |
|
"Tim Thomson" <thomsontim@shaw.ca> wrote in message
news:43C1F0EF.182E5B79@shaw.ca...
> Drums wrote:
<snip>
>
> Nope it's 221
>
Regardless, the standard meter in an 'Edison' residential setup is a
potential coil across the two 'hots' at ~240, and to half-current coils, one
in each leg. The meters compensate for the exact voltage available by use
of a potential sensing coil.
The only time you'll find a kwh meter with only one current leg are those
designed for use in metering 3-phase systems. Some meter hook ups for
3-phase will use three of these types of meters. They are not legal in any
of the states for hook up in 'Edison' (center-tapped 120) service. If you
find one, call your state's public service commission and file a complaint.
But you won't find one. If the utility put one in by mistake ( I *don't*
think it would fit in the same meter enclosure anyway), you could run almost
your entire house on the 'opposite' hot leg and have nil for a utility bill.
Most utilities know people would do it given a chance, so they know better.
As far as the 120/240 heater question, when it comes to the metering, there
is no significant difference. The 120V setup will draw twice the current
(for a given wattage heater), but the kwh meter will only sense it in one of
the 'half-current' coils, and so register the same. A 240V heater of the
same wattage would only draw half the current, but it would be sensed on
*both* half-current coils, and so register the same.
But the higher voltage heater, drawing half the current, means you can use
smaller/cheaper conductors to hook it up (but a more expensive two-pole
breaker).
daestrom
| |
|
| I should add that Nominal varys around here. What's Nominal in my area
may be different elsewhere. Heck if I go 3 blocks over it's different. '
I have seen 125 in some places.
"Drums" <tgiorgi1@REMOVEnycap.rr.com> wrote in message
news:vkDwf.78048$XC4.12505@twister.nyroc.rr.com...
> Sorry, your wrong if you want to be nit picky. RMS 110 is actually over
300
> volts Peek to Peek. ;o)
> And my line volatge is 119.00. Always has been. Lowest I have seen is
115.
>
>
> <barry@sme-online.com> wrote in message
> news:1136834028.594757.179250@f14g2000cwb.googlegroups.com...
>
>
| |
|
|
| SolarFlaire 2006-01-09, 10:21 pm |
| North American standard is 120 Vac RMS +/-10%
117 vac never existed except in the Japanese minds.
"Drums" <tgiorgi1@REMOVEnycap.rr.com> wrote in message
news:VLDwf.57182$XJ5.46691@twister.nyroc.rr.com...
> I should add that Nominal varys around here. What's
Nominal in my area
> may be different elsewhere. Heck if I go 3 blocks
over it's different. '
> I have seen 125 in some places.
>
> "Drums" <tgiorgi1@REMOVEnycap.rr.com> wrote in
message
> news:vkDwf.78048$XC4.12505@twister.nyroc.rr.com...
110 is actually over[color=darkred]
> 300
Lowest I have seen is[color=darkred]
> 115.
news:1136834028.594757.179250@f14g2000cwb.googlegroups.com...[color=darkred]
x2 that's ... right-[color=darkred]
>
>
| |
| Rick Frazier 2006-01-11, 1:21 am |
| Can't say I can remember the particular meter at this time, but back in
time, about 15 years ago in San Jose, California, I was experiencing
some rather high bills that I didn't think were metered correctly. I
put in a number of hour meters (really cheap at the local surplus places
at the time) on the heavy hitters, 120 volt appliances like
refrigerator, central heating fan, clothes washer motor, televisions,
etc, plus some on the 240 volt appliances (range mostly, the remaining
appliances were gas). After some number crunching, it appeared that we
were being overbilled about 50% from my estimates due to hour meters
times draw of the various 120 volt appliances. I noticed that most were
on one side of the 240 volt line, so a few wire swaps later, I had a
decent balance of current. Still had an overbilling of about 25%
according to calculations, despite the fact much of the draw was
balanced (the opposing appliances typically ran at the same times).
After a couple of months of dicing with PG&E, after finally telling them
I had a second meter inside the garage that they couldn't see, which
indicated much closer to my calculated consumption, and if I didn't get
some action I was going to call the local television stations for a
"public interest piece", they finally came out and replaced the meter.
On the new meter, the consumption was within 5% of my calculations, and
even after moving the wires back to their original positions, the
official consumption was only around 7% over my calculations. Close
enough to take care of reasonable measurement, given the method of
gathering the data.
The fellow that came out and replaced the meter indicated that
particular one had problems with imbalanced lines, but it took quite a
lot of convincing before they put out the order to change them out...
Sometimes it pays to be a an electrical engineer and techno-geek [grin]
--Rick
SolarFlaire wrote:
[color=darkred]
> Not in Canada you won't see a meter do that. I have
> seen all the approvals.
>
> Can you state a meter type that can do this?
>
> To aid in your confusion, the run-of-the-mill domestic
> meter has only one potential coil (240V) and two "half"
> current coils, one on each leg. Yes, it's to make it
> cheaper.
>
> Yes on a severely unbalanced ***VOLTAGE*** system there
> can be unfair metering. One leg will meter with it's
> current against half the total voltage. If you are
> loading the low voltage leg then you are getting an
> error against you.
>
> This is only can only be slight (less than about 2%)
> without wires and devices burning up, or bad
> connections causing same usually.
>
> A balanced electrical system is always good as your
> neutral may not be sized to handle the load the line
> legs are.
>
> Now, on some multi unit complexes there is such a thing
> as a "network" meter where three phase power is
> supplied and only two legs and a neutral is supplied
> each unit. This can save on copper. The voltages are
> now at 120 degrees to each other and the voltages would
> classically be 125, 125 and 216 vac. A phase to phase
> load requiring 10 amps at 216 volts would consume 2160
> watts (assuming resistive) the meter would see 10amps x
> 120 volts in each leg and although it would appear to
> add up to 2400 watts there is a 30 degree phase angle
> in each leg so the meter would see 120volts x 10amps x
> cos(30deg) = 1080 watts in each leg for a total of 2160
> watts!
>
> Now VA demand customers get ripped as there are
> differences between arithmetic summation of va and
> phasor addition of va. One favours the utility and one
> favours the customer. Domestic users never have to
> worry about this problem.
>
> Hope that confuses the shit out of ya....LOL
>
> "Rick Frazier" <rickf@rickfrazier.com> wrote in message
> news:43C1D71F.EF371636@rickfrazier.com...
> a given heater
> consumed. However,
> power meters don't
> very well. This is
> metering at 240
> load on 120 volts
> the entire 240 volt
> other side of the
> are some out there
> interests of the power
> makers in the event
> line, or two
> the boundary between
> the other, the net
> heaters of the same
> affecting the actual
> extreme
> side of the 240
> considerably away from
> on the heavily
> loaded side. (This
> chain" wiring is the
> that are less than
> 100 volts on a heavy
> loaded side. This
> higher voltage side of
> newer homes have as
> of the wiring is
> three wire sheaths to
> are two "hot" wires,
> is that the two hot
> the neutral will
> within the current
> Unfortunately, this is not
> if this sort of
> wires on the same side
> both circuits are
> each circuit has a
> which is connected
> with any other
> supposed to be
> present as balanced a
> limits the potential
> line compared to the
> enough to actually
> things like portable
> possible balance.
> plug-in units tend
> wire to 240 volt
> heaters. If you are
> you should at least
> are using portable
> ones you purchase
> disturbed or tipped
> opposite sides of the
> than you normally
> that most baseboard
> square inch
> unattended by a
> minimum 36" spacing
> potential problems
> whatever)
> Yes,
> but
> and
> will
> the
> Much
> that
> power
> how
| |
| SolarFlaire 2006-01-11, 10:21 pm |
| I have these stories 'till they come out of my ears.
They are usually complete bunk and a product of a good
imagination.
I have been involved with over 500,000 electric meters
in my lifetime and I have only seen, or heard, of one
mechanical meter that ever went faster than it should
have. Mechanical gears don't speed up, they grind
slower.
The only way a mechanical meter can speed up was if
your removed the some of the "Damping" or drag
magnetism via a lighning strike or heating the magnets
hot enough to melt the glass.
As far as balanced loads are concerned, in Canada the
Balance between the two side has to be within 1% the
same the other accuracies. Ain't gonna' happen.
Now on an electronic, digtal meter, anything can happen
and I have seen a lot of it.
"Rick Frazier" <rickf@rickfrazier.com> wrote in message
news:43C48F45.780BCE74@rickfrazier.com...
> Can't say I can remember the particular meter at this
time, but back in
> time, about 15 years ago in San Jose, California, I
was experiencing
> some rather high bills that I didn't think were
metered correctly. I
> put in a number of hour meters (really cheap at the
local surplus places
> at the time) on the heavy hitters, 120 volt
appliances like
> refrigerator, central heating fan, clothes washer
motor, televisions,
> etc, plus some on the 240 volt appliances (range
mostly, the remaining
> appliances were gas). After some number crunching, it
appeared that we
> were being overbilled about 50% from my estimates due
to hour meters
> times draw of the various 120 volt appliances. I
noticed that most were
> on one side of the 240 volt line, so a few wire swaps
later, I had a
> decent balance of current. Still had an overbilling
of about 25%
> according to calculations, despite the fact much of
the draw was
> balanced (the opposing appliances typically ran at
the same times).
> After a couple of months of dicing with PG&E, after
finally telling them
> I had a second meter inside the garage that they
couldn't see, which
> indicated much closer to my calculated consumption,
and if I didn't get
> some action I was going to call the local television
stations for a
> "public interest piece", they finally came out and
replaced the meter.
> On the new meter, the consumption was within 5% of my
calculations, and
> even after moving the wires back to their original
positions, the
> official consumption was only around 7% over my
calculations. Close
> enough to take care of reasonable measurement, given
the method of
> gathering the data.
>
> The fellow that came out and replaced the meter
indicated that
> particular one had problems with imbalanced lines,
but it took quite a
> lot of convincing before they put out the order to
change them out...
> Sometimes it pays to be a an electrical engineer and
techno-geek [grin]
>
> --Rick
> SolarFlaire wrote:
>
domestic[color=darkred]
"half"[color=darkred]
it[color=darkred]
there[color=darkred]
it's[color=darkred]
2%)[color=darkred]
line[color=darkred]
thing[color=darkred]
supplied[color=darkred]
are[color=darkred]
would[color=darkred]
phase[color=darkred]
2160[color=darkred]
10amps x[color=darkred]
to[color=darkred]
angle[color=darkred]
10amps x[color=darkred]
2160[color=darkred]
one[color=darkred]
message[color=darkred]
from[color=darkred]
electricity[color=darkred]
line[color=darkred]
and[color=darkred]
ampere[color=darkred]
for[color=darkred]
the[color=darkred]
there[color=darkred]
money[color=darkred]
the[color=darkred]
being[color=darkred]
than[color=darkred]
volt[color=darkred]
imbalance[color=darkred]
one[color=darkred]
voltage[color=darkred]
lightly[color=darkred]
connections[color=darkred]
see[color=darkred]
lightly[color=darkred]
some[color=darkred]
there[color=darkred]
assumption[color=darkred]
current in[color=darkred]
be[color=darkred]
Also,[color=darkred]
if[color=darkred]
cables,[color=darkred]
of[color=darkred]
the[color=darkred]
add[color=darkred]
portable[color=darkred]
running[color=darkred]
volt[color=darkred]
heaters,[color=darkred]
you[color=darkred]
the[color=darkred]
more[color=darkred]
aware[color=darkred]
per[color=darkred]
when[color=darkred]
the[color=darkred]
volts.[color=darkred]
(current)[color=darkred]
your[color=darkred]
confused.[color=darkred]
volts[color=darkred]
case[color=darkred]
twice[color=darkred]
there.[color=darkred]
bucks.[color=darkred]
message[color=darkred]
LOL[color=darkred]
says[color=darkred]
220vac[color=darkred]
him[color=darkred]
>
| |
| Rick Frazier 2006-01-12, 2:21 am |
| Well, you can say all day that you haven't seen one in Canada, and it's
totally possible the meter I encountered was defective in the first
place, or had been modified or mis-calibrated, but I know what I went
through to get the damn thing replaced, and the effect it had on my
electrical bill. No amount of someone in another country posturing
that it "Ain't gonna happen", or alluding to a "good imagination" will
change what happened. As far as a good imagination goes, perhaps we
should examine your claim of being "involved with 500,000 electric
meters".
Let's see, 500,000 meters in a lifetime, let's say you've been in the
industry for 50 years, that's 10,000 meters per year. Given there are
about 230 working days in a year (assuming a five day work week and
about 10 vacation days and another 10 holidays), that's an average of
about 43.48 meters a day, or about 5.8 meters per hour with the typical
7.5 hours of productive work, assuming you NEVER took any extra time off
for a break or was slower due to a bad day or whatever.... Given that
this is a charitable computation, you'd have to "be involved" with a
meter every 10.34 minutes, every day for a fifty year working span.
(YES THAT'S FIFTY YEARS). Now, that makes me just a _little bit_
disinclined to think you have a decent basis for comment. Unless you
were a meter reader from the day you started work until the day you
retired, or were someone "watching them go by" on a production line, I
really doubt your claim of being "involved" with 500,000 meters in a
lifetime. In either case, I really doubt you'd actually see them in a
fashion that would give you a decent basis for comment. Actually
"seeing" that many meters (or a smaller number of meters that many
times) has nothing to do with how they operate.
So much for self proclaimed internet "experts" making outlandish
claims. I only related my experience with a particular meter that
obviously was over charging for an unbalanced load. It was also
overcharging for a balanced load, but not as badly. I've seen it, I
documented it, and I got the utility to replace in eventually (and got a
slight adjustment on my previously paid bills, though not near enough
for what I think I'd been overcharged). I don't doubt that the meter
was in a relative minority of units that didn't operate as one would
expect, but I've seen more than enough shady operations to suspect that
there have been some "accidental miscalibration" events from time to
time....
Have a nice life... Plonk!
SolarFlaire wrote:
[color=darkred]
> I have these stories 'till they come out of my ears.
> They are usually complete bunk and a product of a good
> imagination.
>
> I have been involved with over 500,000 electric meters
> in my lifetime and I have only seen, or heard, of one
> mechanical meter that ever went faster than it should
> have. Mechanical gears don't speed up, they grind
> slower.
>
> The only way a mechanical meter can speed up was if
> your removed the some of the "Damping" or drag
> magnetism via a lighning strike or heating the magnets
> hot enough to melt the glass.
>
> As far as balanced loads are concerned, in Canada the
> Balance between the two side has to be within 1% the
> same the other accuracies. Ain't gonna' happen.
>
> Now on an electronic, digtal meter, anything can happen
> and I have seen a lot of it.
>
> "Rick Frazier" <rickf@rickfrazier.com> wrote in message
> news:43C48F45.780BCE74@rickfrazier.com...
> time, but back in
> was experiencing
> metered correctly. I
> local surplus places
> appliances like
> motor, televisions,
> mostly, the remaining
> appeared that we
> to hour meters
> noticed that most were
> later, I had a
> of about 25%
> the draw was
> the same times).
> finally telling them
> couldn't see, which
> and if I didn't get
> stations for a
> replaced the meter.
> calculations, and
> positions, the
> calculations. Close
> the method of
> indicated that
> but it took quite a
> change them out...
> techno-geek [grin]
> domestic
> "half"
> it
> there
> it's
> 2%)
> line
> thing
> supplied
> are
> would
> phase
> 2160
> 10amps x
> to
> angle
> 10amps x
> 2160
> one
> message
> from
> electricity
> line
> and
> ampere
> for
> the
> there
> money
> the
> being
> than
> volt
> imbalance
> one
> voltage
> lightly
> connections
> see
> lightly
> some
> there
> assumption
> current in
> be
> Also,
> if
> cables,
> of
> the
> add
> portable
> running
> volt
> heaters,
> you
> the
> more
> aware
> per
> when
> the
> volts.
> (current)
> your
> confused.
> volts
> case
> twice
> there.
> bucks.
> message
> LOL
> says
> 220vac
> him
| |
|
| Rick Frazier wrote:
> In the simplest look, the amount of BTU you get from a given heater
> should be the same, given the watts of electricity consumed. However,
> that said, you should also bear in mind that some power meters don't
> handle high current on one side of the 240 volt line very well. This is
> primarily due to the electric company providing and metering at 240
> volts. I've seen a few that will meter a 10 ampere load on 120 volts
> (one side only) as if it were a 10 ampere load for the entire 240 volt
> service, unless there is a corresponding load on the other side of the
> line. Not all meters have this problem, but there are some out there
> that still do. It's not exactly in the best interests of the power
> company to replace these meters, as they are money makers in the event
> you present an unbalanced load.
>
Sorry to butt in, but do I understand from your answer that the standard
US grid connection is a 2 phase 120v system with 180 degree separation?
If so, I have been labouring under a misconception for a long time about
the US distribution system... I always thought it was just a plain
simple 110v.
I'm an electrical technician here in Australia, where standard supply is
240v single phase, or 240v three phase with 120 degree separation,
giving 415v between phases. I believe (though I've never worked on one)
some of the old rural supplies (SWER lines they're called - Single Wire
Earth Return) are 440v single phase split at the consumption end by a
transformer to 2 phase 220v at 180 degrees.
| |
| RF Dude 2006-01-23, 9:21 pm |
| North America has 120/240V (not 110V) single phase for most residences. Some
people mistakenly call this 2 phase, but it is only 180 degree halves of one
phase. Two "legs" off a transformer with a center tap to ground.
So stanard root 3 applies and you get 120/208V in a three phase system.
Within a large building in the US, it usually uses 277/480V distribution
with transformers to step down to 120/208V where required. In Canada, they
more commonly use 347/600V.
Regarding the other comments about utility meters not doing well with single
phase loads... that's news to me. Anyone else care to elaborate?
> Sorry to butt in, but do I understand from your answer that the standard
> US grid connection is a 2 phase 120v system with 180 degree separation? If
> so, I have been labouring under a misconception for a long time about the
> US distribution system... I always thought it was just a plain simple
> 110v.
>
> I'm an electrical technician here in Australia, where standard supply is
> 240v single phase, or 240v three phase with 120 degree separation, giving
> 415v between phases. I believe (though I've never worked on one) some of
> the old rural supplies (SWER lines they're called - Single Wire Earth
> Return) are 440v single phase split at the consumption end by a
> transformer to 2 phase 220v at 180 degrees.
| |
| Solar Flare 2006-01-23, 10:21 pm |
| The only examples I can think of for Network type
meters/services goes likes this.
You have a rectithermal VA type demand meter displaying
Arithmetic VA.
It has two elements that measure the VA on each legs of
the Network service 125/216 volts
Given a load of 2160 watts @ 1.00 pf = 2160 VAs or 10
Amperes @ 216 Volts.
The meter measures on each element 10 amperes x 125
volts = 1250 VAs for a total of 2500 VAs
This arithmetic VA method can be justified depending on
which side of the meter you are on. The wires through
the wall each carry 10 amperes or 1250 VAs and this is
what the demand charge is really for. (Fair to the
utility)
The phasor (vectorial) VA method of measurement would
indicate 2160 VAs = the customer's load (Fair to the
customer). However with this method of measurement a
customer with a VA demand meter could power factor
correct the crap out of one phase and correct for the
other phase(s) involved. (unfair to the utility). In
this extreme example an Arithmetic VA demand would read
extremely high and the Phasor VA demand meter would
read extremely low.
None of these examples apply to residential kWh
(consumption) only metering. Extreme examples of
metering errors do not exist on residential metering.
There is an example that can generate errors on kWh
meters used incorrectly.
Where a 3 wire single phase service is converted to a
two phase 120 degree potential service (3ph 4w one leg
missing) then phase to neutral unbalance (120 volt)
loads will not be measured correctly. The phase to
phase pot coil in the single phase meter will measure
1/2 the voltage x the neutral current.
e.g.. With a single 120 volt @ 10 ampere load = 1200
Watts = 1200 VAs
the meter would see 208 volts x 1/2 of 10 amperes
= 1040 VAs x cos(30 deg)= 901 Watts
= 25% low (unfair to the utility)
This only works for the unbalanced load on the service.
For balanced and phase to phase (240 volt) loads all is
measured correctly.
Too many years of professional metering error analysis.
"RF Dude" <post@thisnewsgroup.com> wrote in message
news:0yeBf.4136$ft2.90331@news20.bellglobal.com...
> Regarding the other comments about utility meters not
doing well with single
> phase loads... that's news to me. Anyone else care
to elaborate?
|
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