Monitoring electricity consumption of a device?

This may be of interest to you:
http://www.brandelectronics.com/powermeter.htm
I've not used one, but I had bookmarked the page, as it had gotten pretty
good reviews in another NG I read regularly.

Alternately, find a rundown, abandoned house with a meter still in the box,
and borrow it (just kidding, of course). If it's really old, the power co.
would replace it anyway. Maybe even ask a power co employee if they can get
you an obsolete meter. Sometimes the rural electric coops are easier to
deal with. They are all changing over to the meters that can be read from
the truck via RF.

HTH,
Joe

wrote:

I'm building what I believe will be a super high efficiency electric
furnace utilizing engineering technology overlooked by studio glass
makers. But I need a method to prove my energy usage so I can present
my findings. Besides thorough documentation of my charge and idle
cycles, I need a meter that will work with a phase-angle SCR. I'm not
familiar with any device that can monitor my usage through an SCR. With
an inductive ammeter, one would need a constant graph since current
draw flucuates wildly from moment to moment. Any usenet folks out there
have any ideas?

Hi Mike. As Jack pointed out, many of us have controllers that are
sophisticated enough to allow percentage-wise control of the output
signal. This can be used for various purposes, notably in our case, to
reduce watt-loading of elements. For example if your heater draws 60a,
you might set your output signal at 50% so that the elements are not
taxed at their maximum. Simply, a way of current limiting from the
controller. I don't use that feature however, because my scr has a
built in current limiter that can be set.

The analog clock will work with a mechanical relay or a mercury relay.
I would be very skeptical about it working with a burst-fire ssr under
any circumstances, but wtfdik.

I really have to avoid a very complicated system, Mike. If it is as you
say, and a particular type of current meter won't work, I'll just run
the furnace and know it is very efficient but not quantifiable.
Because, I don't build furnaces for a living, and I'm not writing a
dissertation. I have to make glass for a living.

PS. Errata in reference to the clock I meant an *SSR or a burst fire
SCR.*

The analog clock will work with a mechanical relay or a mercury relay.
I would be very skeptical about it working with a burst-fire ssr under
any circumstances, but wtfdik.
Works fine on my rig. The signal coming off an SSR with zero crossing
(not phase control) is exactly what goes in. If the not too radical
assumption is made that it starts pretty quick at power on and only coasts a
bit on power off, then it records the length of the on-time. My controller
tends to stay on till the controller sees how the power affects the temp (it
"learns") and then at temp, it stays off for many seconds and on for a few
seconds, so the analog clock works. At one time, I stood there with a stop
watch and timed the indicator light and found the watch and the clock were
matched close enough for my purposes.

--
Mike Firth
No more levees
Bury old Orleans
Raise New Orleans up if it is worth saving
--
wrote in message
oups.com...
Hi Mike. As Jack pointed out, many of us have controllers that are
sophisticated enough to allow percentage-wise control of the output
signal. This can be used for various purposes, notably in our case, to
reduce watt-loading of elements. For example if your heater draws 60a,
you might set your output signal at 50% so that the elements are not
taxed at their maximum. Simply, a way of current limiting from the
controller. I don't use that feature however, because my scr has a
built in current limiter that can be set.

The analog clock will work with a mechanical relay or a mercury relay.
I would be very skeptical about it working with a burst-fire ssr under
any circumstances, but wtfdik.

I really have to avoid a very complicated system, Mike. If it is as you
say, and a particular type of current meter won't work, I'll just run
the furnace and know it is very efficient but not quantifiable.
Because, I don't build furnaces for a living, and I'm not writing a
dissertation. I have to make glass for a living.

If your goal is to develop a kiln that holds the heat more efficiently,
I suspect you'll find only the hobbyists are interested. Production
kilnformers usually want kilns that lose heat faster. Many build kilns
with fibreboard instead of bricks for specifically that reason. The
objective is to get the heat out as quickly as is safely possible so
you can fire the kiln more frequently. Most existing glass kilns lose
heat too slowly. Why would somebody want one that's even slower? The
cost of electricity is too small to be of consequence. My calculations
are it's about 1% of the value of each load.

I'd be happy to pay for 10 times as much electricity if I could cool
the kiln twice as fast.

wrote in message
oups.com...

I'd be happy to pay for 10 times as much electricity if I could cool
the kiln twice as fast.

Ummmm....that's what fans are made for.

This is a glass furnace Dennis. Its a completely different animal than
a kiln. But, In a world of runaway fuel costs even kiln formers should
be looking at ways ways to increase efficiency. There are ways to
increase efficiency vastly in kilnforming. Heating up and cooling down
for a few pieces is why most kilnformers will never make it pay. And
beyond that you'll have to figure out the secret yourself.

By way of background, glass blowers are generally told that furnace
efficiency has a defined limit. You can only insulate so much, beyond
which you start progressing backward in efficiency, due to the
increased radiant surface area of the furnace.

I have always had a problem with that fatalism. It has seemed to me
very uninspired thinking. My new furnace takes advantage of technology
my brother (He's a phd in materials science) and I have discussed over
the years. It has to do with strategizing to limit both conductive and
radiant heat loss, and emmissivity of metal surfaces. Beyond that...

Also, I have been very interested in cogeneration from glass furnaces.
Some of our learned scholars in the glass world believe profit in this
regard violates the second law of thermodynamics; I plan to grow
lucious avocados in Oregon in January AND have a super efficient
furnace--which is proof enough for me. My new furnace will lend itself
to co-generation, when I have time to do it. Or when gas hits six bucks.

Well, your reason most people think adding more insulation not cost
effective is wrong. Most people who have done measurements feel that the
gain in efficiency after a certain point (about 11") is not worth the money
spent on the insulation. Why spend $100 on insulation that saves 1% over
the previous savings? And you have to live with a really bulky furnance
with a hole in the side that is really deep to get into the glass.
I have asked the question: Since Ceramic Fiber's special insulation
mechanism basically works at higher temps (according to the makers) and it
works by air entrainment at lower temps, why not use ceramic fiber ($$$) at
inner walls and when you get the inside the wall temp down below glass
melting temp, use cheap fluffy fiberglass insulation?
And Henry Havens has mentioned publicly online that he uses a stainless
steel tube with holes drilled in it and low pressure air to increase the
evenness of heat in a kiln during annealling but if too much air is put in,
it cools the kiln, which is sometimes desireable.

--
Mike Firth
No more levees
Bury old Orleans
Raise New Orleans up if it is worth saving
--
wrote in message
ups.com...
This is a glass furnace Dennis. Its a completely different animal than
a kiln. But, In a world of runaway fuel costs even kiln formers should
be looking at ways ways to increase efficiency. There are ways to
increase efficiency vastly in kilnforming. Heating up and cooling down
for a few pieces is why most kilnformers will never make it pay. And
beyond that you'll have to figure out the secret yourself.

By way of background, glass blowers are generally told that furnace
efficiency has a defined limit. You can only insulate so much, beyond
which you start progressing backward in efficiency, due to the
increased radiant surface area of the furnace.

I have always had a problem with that fatalism. It has seemed to me
very uninspired thinking. My new furnace takes advantage of technology
my brother (He's a phd in materials science) and I have discussed over
the years. It has to do with strategizing to limit both conductive and
radiant heat loss, and emmissivity of metal surfaces. Beyond that...

Also, I have been very interested in cogeneration from glass furnaces.
Some of our learned scholars in the glass world believe profit in this
regard violates the second law of thermodynamics; I plan to grow
lucious avocados in Oregon in January AND have a super efficient
furnace--which is proof enough for me. My new furnace will lend itself
to co-generation, when I have time to do it. Or when gas hits six bucks.

Right Mike,,, Henry Havens? You're drunk, right?

At a given thickness (generally agreed to be 7-8" by longtime furnace
builders and engineers) Conductive heat loss through packed fiber is
not reduced in proportion to the radiant heat loss from the surface.
Efficiency proceeds in reverse. That's the theoretical point.The
practical point is, yes at some point additional fiber cost begins to
outweigh energy savings. But even if fiber were free, it still wouldn't
make sense. Remember that fiber is an insulator, but it also conducts
heat energy. In general conductive heat transfer is the most efficient
form of heat transfer. But don't get the wrong idea, obviously the
sheer volume of radiant heat loss per unit area of surface surpasses
the conductive heat loss of an insulating material, at some minimum
level. Ask a guy with an under-insulated furnace. So, you see we aren't
dealing with absolutes, but defined equations. Too much either way, and
efficiency is reduced.

My point is, the fact that you can't insulate further with a conductive
material is not the end of the story. Efficiency can and has been
increased by engineering techniques that are used outside the studio
glass arena.The trick is to limit heat transfer via conduction, while
also limiting the corresponding increase in radiant heat loss per unit
area. A hint, air is one of our best insulators, and it is free. It
insulates well because of its low heat conductivity. However, it is a
great medium for radiant heat loss. Which also fiber is not... and so
on, and so on...

As a side note, efficiency can also be increased by investing some
additional energy in stopping loss from the system.So that, while the
overall energy used by the system is increased, the proportion of
energy within the system put to work, not lost to the surroundings, has
increased. This activity can take different forms.

Mike Firth wrote:

Well, your reason most people think adding more insulation not cost
effective is wrong. Most people who have done measurements feel that the
gain in efficiency after a certain point (about 11") is not worth the money
spent on the insulation. Why spend $100 on insulation that saves 1% over
the previous savings? And you have to live with a really bulky furnance
with a hole in the side that is really deep to get into the glass.
I have asked the question: Since Ceramic Fiber's special insulation
mechanism basically works at higher temps (according to the makers) and it
works by air entrainment at lower temps, why not use ceramic fiber ($$$) at
inner walls and when you get the inside the wall temp down below glass
melting temp, use cheap fluffy fiberglass insulation?
And Henry Havens has mentioned publicly online that he uses a stainless
steel tube with holes drilled in it and low pressure air to increase the
evenness of heat in a kiln during annealling but if too much air is put in,
it cools the kiln, which is sometimes desireable.


That's Henry Halem. Henry Havens was that guy that sang at Woodstock.

--
Jack

Plonked by Native American

bobo1148atxmissiondotcom


http://photos.yahoo.com/bc/xmissionbobo/