Greetings All,
I would like to show the actual dollar savings if we shut down machinery at
work during lunchtime. I know basic electric theory, but could use a hand
from someone with an industrial background.
Basically, no one is shutting down our punch presses during breaks. The
motors are 3 phase and either 220 or 440. I could find out the kilowatt
rates that we pay. What else do I need and how do I plug the numbers in to
come up with
a dollar amount for every hour that they let the motor run? I know that I
need the amperage from the motor nameplate.
I have seen electric questions here bring on a flood of both replies and
arguments, I don't want to see that happen. If the thread gets too long,
just let it die and we'll all keep to WWing........ Many thanks, Mark
"mark" wrote:
> Basically, no one is shutting down our punch presses during breaks.
The answer to your question lies in the application, namely punch presses.
The motor is connected to a flywheel which stores energy to be delivered to
the punch when the clutch is activated.
When the punch is made, the flywheel slows down and delivers the energy to
the punch to make the part.
The balance of the cycle is used to bring the flywheel back to design RPM.
As soon as that happens, the motor basically coasts consuming minimum power.
So during your breaks, the press is basically operating at idle or minimum
power consumption.
If the press were to be shut off, the flywheel would coast to a stop losing
all it's stored energy, then you would have to replace all that energy by
bringing the flywheel up to speed before starting operations.
This is a case where keeping the press running during breaks is probably the
most cost effective operating procedure.
Lew
"mark" wrote:
> I'm kind of torn as to whether the restarting will draw more current than
> what is saved during the lunches.
The only way to know for sure it to hook up a recording KWH meter for a
couple of weeks.
Test1:
Let the press run continuously.
Test2:
Stop the press during breaks.
Run each test for a week and compare results.
Lew
Leon wrote:
>
> "mark" <[email protected]> wrote in message
> news:[email protected]...
>> Greetings All,
>> I would like to show the actual dollar savings if we shut down machinery
>> at work during lunchtime. I know basic electric theory, but could use a
>> hand from someone with an industrial background.
>> Basically, no one is shutting down our punch presses during breaks. The
>> motors are 3 phase and either 220 or 440. I could find out the kilowatt
>> rates that we pay. What else do I need and how do I plug the numbers in
>> to come up with
>> a dollar amount for every hour that they let the motor run? I know that I
>> need the amperage from the motor nameplate.
>> I have seen electric questions here bring on a flood of both replies and
>> arguments, I don't want to see that happen. If the thread gets too
>> long,
>> just let it die and we'll all keep to WWing........ Many thanks, Mark
>>
>>
>>
>
> The really simplest and accurate answer is to simply shut the machinery
> down as prescribed for an electrical billing period and compare that bill
> to a same length period of not shutting the machinery down.
The only problem with that is if other conditions vary between billing
cycles (temperature, lighting needs, etc.). Those other conditions can
skew the results and lead to very erroneous conclusions. Since the savings
on this may be very subtle, those confounding conditions may swamp out the
real results.
--
If you're going to be dumb, you better be tough
Robatoy took a can of maroon spray paint on January 20, 2008 01:16 pm and
wrote the following:
> On Jan 20, 12:19Â pm, [email protected] wrote:
>> You could suggest your employer install a motion detecting switch
>> (very inexpensve) in all neccesary rooms. We have them all around the
>> shop and office.
>
> I did this at my house.
Me too, the best one is between our bedroom and the bathroom, handy in the
middle of the night, there is only a 15Watt bulb in the light, it doesn't
wake me up, just makes sure I don't trip over a cat.
--
Lits Slut #9
Life would be so much easier if we could just look at the source code.
On Jan 20, 11:20=A0am, "J. Clarke" <[email protected]> wrote:
> Lumpy wrote:
> > Am I missing something here?
>
> > MONDAY:
> > 1159hrs - read meter
> > 1200hrs - go to lunch, leave machines on.
> > 1259hrs - return from lunch read meter
>
> > TUESDAY:
> > 1159hrs - read meter
> > 1200hrs - go to lunch, turn machines off.
> > 1259hrs - return from lunch, turn machines on, read meter
>
> > Compare kwh readings
>
> Yes, you are missing something. =A0That method does not account for
> other loads in the building.
>
> --
> --
> --John
> to email, dial "usenet" and validate
> (was jclarke at eye bee em dot net)
That is how I would do it. If you are worried about other loads in
the building, do it everyday for a week. That should factor out the
unusual loads (statistically speaking). This would get you pretty
close.
Montyhp
"mark" <[email protected]> wrote in message
news:[email protected]...
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery
> at work during lunchtime. I know basic electric theory, but could use a
> hand from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies and
> arguments, I don't want to see that happen. If the thread gets too long,
> just let it die and we'll all keep to WWing........ Many thanks, Mark
>
>
>
Oh Mark - you're biting off quite a piece here. There's more to it than the
cost of the electricity to keep machines running., There's the cost of
start/stop. On many machines, the hardest part of their lives is when they
start/stop, The overall maintenance costs may well exceed any savings from
shutting them down for a lunch hour.
--
-Mike-
[email protected]
"mark" <[email protected]> wrote in message
news:[email protected]...
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery
at
> work during lunchtime. I know basic electric theory, but could use a hand
> from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies and
> arguments, I don't want to see that happen. If the thread gets too long,
> just let it die and we'll all keep to WWing........ Many thanks, Mark
>
>
>
Punch presses have large fly wheels that require significant amounts of
energy to get them up to speed. Once at speed they require very little power
to keep them running. It's quite common for these presses to be left running
during breaks and lunch as a means of reducing the electrical power that is
required to run them. In fact, the fly wheels of the larger ones are likely
to still be turning after being powered off and left for a half hour period.
Starting one and bringing it up to speed requires much more power than
running it at speed for several hours. Long ago this fact was realized, and
this is why they are left running as a common practice.
Charley
Lumpy wrote:
> Lump:
>
>>>Power consumption is power consumption.
>>>All other factors being equal, measure the
>>>consumption with the stuff shut down, vs
>>>the stuff running. The "other loads" are constant
>>>if you do the experiment correctly.
>
>
> Doug Miller:
>
>>Yes, except that "correctly" means
>>comparing long-term averages, not
>>two individual days as you suggested originally.
>
>
> Again, other factors don't figure in if the only
> variable is the machine on or off factor.
>
> January or August, night or day. The machines
> draw XX current. Do the experiment for two days
> or do it for 90 days and divide back to get single
> day figures.
>
> Machines draw XX amps when continually running and not used.
> Machines draw ZZ amps when shut off then back on 59 minutes
> later.
>
> Only factor at all I can see skewing the results would be if
> some workers came back early from lunch and turned their
> machines on. That would probably be mitigated by other
> workers returning late.
>
> The guy is looking for a reason to suggest that they either
> leave them on or off during lunch. I don't think he's looking
> for the ability to guess within 3 cents how much they'll save.
> It's the general trend that counts.
>
>
> Lumpy
>
> You Played on Lawrence Welk?
> Yes but no blue notes. Just blue hairs.
>
> www.LumpyGuitar.net
>
>
>
>
One of the things only hinted about is the number of these presses (and
"other loads") that would be restarted after lunch/break. several
lifetimes ago, when I worked in a mill in the early 70's, the mill
couldn't start all of it's equipment at the same time or they'd actually
drop the main fuses feeding the transformers to the facility.... Sounds
really odd, but the startup currents were so great in proportion to the
running current it happened more than once while I worked there.
Initially, they seemed to rely on the variability of the workers in
solving the problem, IE, you'd find the people that worked there the
longest tended to take the longest time to "get ready" and finally power
up their machines, while the newbies would be hitting the switch nearly
as soon as the whistle went off... Many of the big machines had
manually operated starting switches, so the operator would pull the
lever on the fusebox/starting switch, hold it until the motor spun up
most of the way, then slam it to the operating position. Too early and
the motor either failed to "catch" or it blew the fuses. It never
seemed to hurt to hold it in the start position a few seconds longer,
but you'd get some really strange looks from the millwrights if you did...
So, in a nutshell, there are a LOT more variables to stopping and
starting larger mill/machine shop operations than you might originally
think about... The cost of idling over lunch may be a small cost to pay
(even if the electricity costs more than shutting the machines down)
compared to the amount of lost work time (labor) if the machines don't
all come up right away after the break....
Thanks
--Rick
On Jan 19, 10:42 pm, "mark" <[email protected]> wrote:
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery at
> work during lunchtime. I know basic electric theory, but could use a hand
> from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies and
> arguments, I don't want to see that happen. If the thread gets too long,
> just let it die and we'll all keep to WWing........ Many thanks, Mark
Well i know a bit on these subjects.
Odds are you would save more making sure the bearings for the presses
flywheel are in top shape. when in idle the motor is barely drawing
anything its just making up for the friction losses of the flywheel.
the simplest way to explain power factor correction is that it cuts
the amperage of the motor under load in exchange for a HUGE increase
in the amperage draw on idle. Its a good thing to compensate for on
motors under constant heavy load but not on intermittently used motors
(Saws Hammers etc)
the best way to figure out the difference would be to put a Power
meter (KWH meter) on a tool and sample for a time doing it one way
then for a time doing it the other.
I think you'll find the difference is trivial in the power use on
turning it off and on once you figure out your power billing formula.
but overall if there are friction losses in the flywheel area that you
can counter those would add up in the long run. if you can drop the
idel draw by having better bearings that let the flywheel lose less
energy and deliver more energy to the hammer and it will let the motor
spool the hammer back up to speed more efficiently.
Basically if there is any extra friction in the mechanicla workings of
the tool ot will increase the current draw significantly more in all
states and fixing that long term will save far more than turning off
the hammer for a break.
Brent
Ottawa Canada
Am I missing something here?
MONDAY:
1159hrs - read meter
1200hrs - go to lunch, leave machines on.
1259hrs - return from lunch read meter
TUESDAY:
1159hrs - read meter
1200hrs - go to lunch, turn machines off.
1259hrs - return from lunch, turn machines on, read meter
Compare kwh readings
Lumpy
You were the Tidy Bowl Guy?
Yes. I'm cleaning your bathroom bowl.
www.LumpyVoice.com
Lumpy wrote:
> > Am I missing something here?
> >
> > MONDAY:
> > 1159hrs - read meter
> > 1200hrs - go to lunch, leave machines on.
> > 1259hrs - return from lunch read meter
> >
> > TUESDAY:
> > 1159hrs - read meter
> > 1200hrs - go to lunch, turn machines off.
> > 1259hrs - return from lunch, turn machines on, read meter
> >
> > Compare kwh readings
J. Clarke:
> Yes, you are missing something. That method does not account for
> other loads in the building.
Please explain what "other loads" will be
mis-accounted when doing the comparison readings.
Lumpy
You were the Tidy Bowl Guy?
Yes. I'm cleaning your bathroom bowl.
www.LumpyVoice.com
Leon wrote:
> ... in a factory production setting I doubt that
> lighting would be different and there may be no air conditioning but
> if you take ajasent billing periods you may not have much deviation
> at all on temperature.
Change the experiment parameters every other day.
That mitigates the seasonal things like HVAC.
Simple enough on our residential meters here
in AZ.
Lumpy
You were the "OPERATION" game voice?
Yes. Take out wrenched ankle.
www.LumpyVoice.com
J. Clarke:
> > > Yes, you are missing something.
> > > That method does not account for
> > > other loads in the building.
Lump:
> > Please explain what "other loads" will be
> > mis-accounted when doing the comparison readings.
J. Clarke:
> Since I have not seen the facility I have no idea.
> Since you have not
> seen it you have no idea either.
So you think I'm missing something that you
have no idea about?
Power consumption is power consumption.
All other factors being equal, measure the
consumption with the stuff shut down, vs
the stuff running. The "other loads" are constant
if you do the experiment correctly.
Lumpy
You were on CHiPs? Did you wear those sexy
tight pants and high boots like Erik Estrada?
No. Swimtrunks.
www.LumpyMusic.net
Lump:
> > Power consumption is power consumption.
> > All other factors being equal, measure the
> > consumption with the stuff shut down, vs
> > the stuff running. The "other loads" are constant
> > if you do the experiment correctly.
Doug Miller:
> Yes, except that "correctly" means
> comparing long-term averages, not
> two individual days as you suggested originally.
Again, other factors don't figure in if the only
variable is the machine on or off factor.
January or August, night or day. The machines
draw XX current. Do the experiment for two days
or do it for 90 days and divide back to get single
day figures.
Machines draw XX amps when continually running and not used.
Machines draw ZZ amps when shut off then back on 59 minutes
later.
Only factor at all I can see skewing the results would be if
some workers came back early from lunch and turned their
machines on. That would probably be mitigated by other
workers returning late.
The guy is looking for a reason to suggest that they either
leave them on or off during lunch. I don't think he's looking
for the ability to guess within 3 cents how much they'll save.
It's the general trend that counts.
Lumpy
You Played on Lawrence Welk?
Yes but no blue notes. Just blue hairs.
www.LumpyGuitar.net
Doug Miller wrote:
> Trouble is, you don't know what other loads
> might be in use elsewhere in the building -
> - suppose one of the two days you decide to
> conduct your experiment happens to be the same
> day that the welders are working through lunch
> on a major rush project. That's certainly going
> to skew your meter readings...
Of course that's a potential factor. So when you
do the experiment, or when you interpret the findings,
you do as any good experimenter should and try to
reduce or eliminate the other variables. When the
figures tend to show something you ask "were the
welders working on that rush project then?".
> Your sig is still malformed.
My sig is formed exactly the way I want it formed.
Lumpy
You were able to retire by doing all those voices?
Yes. You don't see me punching a clock, do you?
www.LumpyVoice.com
On Jan 20, 12:19=A0pm, [email protected] wrote:
> You could suggest your employer install a motion detecting switch
> (very inexpensve) in all neccesary rooms. We have them all around the
> shop and office.
I did this at my house.
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
>
> "Owen Lawrence" wrote:
>
>> Sorry, I'm not buying your logic.
>
> Not a problem.
>
> My response was not an absolute answer, rather was an indication of
> probable results.
>
> There are too many variables to give a definitive answer with out actual
> test data which is why my post about using recording KWH meter.
>
> Lew
Yup. Once I actually witnessed two PhD engineers sparring this way;
eventually one of them (a professor doing expensive consulting for the
company) finally threw up his hands and said, practically shouting, "Aww
don't introduce another variable!"
But it's fun to chat, anyway. I hope the OP finds what he needs.
- Owen -
In article <[email protected]>, "Lumpy" <[email protected]> wrote:
>
>Power consumption is power consumption.
>All other factors being equal, measure the
>consumption with the stuff shut down, vs
>the stuff running. The "other loads" are constant
>if you do the experiment correctly.
Yes, except that "correctly" means comparing long-term averages, not two
individual days as you suggested originally.
Your sig is still malformed. Just thought you'd like to know.
--
Regards,
Doug Miller (alphageek at milmac dot com)
It's time to throw all their damned tea in the harbor again.
"Andrew Erickson" <[email protected]> wrote in message
> Given that this is (presumably) an industrial/commercial utility
> account, the rates may well be more complicated than just $x per kWh
> used, with adjustments or charges made for peak loads, power factors,
> moon phases, and your deity of choice only knows what else.
>
True. Considering the power factor, starting all those machines at the same
time you can push up the power factor and actually increase the cost as
compared to running at no load for 30 minutes.
Frankly, I don't completely understand the power factor thing (it can be
corrected with capacitors) but it will probably take an EE to get an
accurate assessment of the situation.
The simplistic approach is to take the nameplate x kWh rate and get a raw
number. If management does not know any better they may accept your
numbers, give you a big bonus and think they are saving a bundles.
Realistically, you'd want to check the current draw at a minimum, using an
Amprobe. Check that start up though, it may be quite costly.
"Twayne" <[email protected]> wrote in message
news:elQkj.21582$8A4.5385@trnddc02...
> Lumpy <[email protected]> wrote:
>> Am I missing something here?
>>
>> MONDAY:
>> 1159hrs - read meter
>> 1200hrs - go to lunch, leave machines on.
>> 1259hrs - return from lunch read meter
>
>
>
> If those numbers are real/accurate, it would indicate that the machinery
> in question is actually pretty small stuff and thus an insignificant part
> of the overal power usage. That small a KWH usage there wont' be much
> difference period.
> So, compared to the overall usage, whatever machines those are would be
> insignificantly small enough to be negligible.
>
> Twayne
What numbers are you talking about? All I see is the time he goes to lunch,
reads the meter and returns from lunch.
"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> "Leon" <[email protected]> wrote in message
>>
>> The really simplest and accurate answer is to simply shut the machinery
>> down as prescribed for an electrical billing period and compare that bill
>> to a same length period of not shutting the machinery down.
>
> This is a USENET newsgroup. We don't want simple answers. We can stand
> simple answers. Please, don't confuse us with facts.
>
Umm,, sorry. I'll try to make it more complicated next time. LOL
"mark" <[email protected]> wrote in message
news:[email protected]...
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery
> at work during lunchtime. I know basic electric theory, but could use a
> hand from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies and
> arguments, I don't want to see that happen. If the thread gets too long,
> just let it die and we'll all keep to WWing........ Many thanks, Mark
>
>
>
The really simplest and accurate answer is to simply shut the machinery down
as prescribed for an electrical billing period and compare that bill to a
same length period of not shutting the machinery down.
"Mark & Juanita" <[email protected]> wrote in message
news:[email protected]...
> Leon wrote:
>
> The only problem with that is if other conditions vary between billing
> cycles (temperature, lighting needs, etc.). Those other conditions can
> skew the results and lead to very erroneous conclusions. Since the
> savings
> on this may be very subtle, those confounding conditions may swamp out the
> real results.
I can see that but in a factory production setting I doubt that lighting
would be different and there may be no air conditioning but if you take
ajasent billing periods you may not have much deviation at all on
temperature.
In article <[email protected]>, "Lumpy" <[email protected]> wrote:
>Doug Miller wrote:
>> Trouble is, you don't know what other loads
>> might be in use elsewhere in the building -
>> - suppose one of the two days you decide to
>> conduct your experiment happens to be the same
>> day that the welders are working through lunch
>> on a major rush project. That's certainly going
>> to skew your meter readings...
>
>Of course that's a potential factor. So when you
>do the experiment, or when you interpret the findings,
>you do as any good experimenter should and try to
>reduce or eliminate the other variables.
Which means measuring over a long enough time period to eliminate, or at least
reduce to insignificance, the effect of random events on the quantity being
measured.
--
Regards,
Doug Miller (alphageek at milmac dot com)
It's time to throw all their damned tea in the harbor again.
"Lumpy" <[email protected]> wrote in message
news:[email protected]...
> Am I missing something here?
>
> MONDAY:
> 1159hrs - read meter
> 1200hrs - go to lunch, leave machines on.
> 1259hrs - return from lunch read meter
>
> TUESDAY:
> 1159hrs - read meter
> 1200hrs - go to lunch, turn machines off.
> 1259hrs - return from lunch, turn machines on, read meter
>
> Compare kwh readings
Yeah that would be way too simple. Big electricity purchasers also have to
factor in the extreme loads in addition to the amount of kilowatts that they
consume. You really have to see how the electricity provider interprets
your usage to determine if there is a savings or not.
"Leon" <[email protected]> wrote in message
>
> The really simplest and accurate answer is to simply shut the machinery
> down as prescribed for an electrical billing period and compare that bill
> to a same length period of not shutting the machinery down.
This is a USENET newsgroup. We don't want simple answers. We can stand
simple answers. Please, don't confuse us with facts.
In article <cLtlj.4234$Ev6.1193@trndny07>, dave <""david.stehman\"@no spamverizon.net"> wrote:
>why are you giving the employees off for lunch? cant they eat a sandwich
>while they're working ;-)
Naah, it gets mustard in the punch presses. Corrosive, you know.
--
Regards,
Doug Miller (alphageek at milmac dot com)
It's time to throw all their damned tea in the harbor again.
I'm kind of torn as to whether the restarting will draw more current than
what is saved during the lunches. It only takes app 20 seconds to spool up
the motor to a ready state, so I'm guessing that is more than offset by the
35 minutes it would be shut off. And additionally, there are also scrap
chutes which are powered by separate motors. And we would be saving on the
wear and tear by running at least 2 hours less 5 or 6 days a week. All
totaled, the machines would run app 2 1/2 hours less per day (we run 2
shifts), 12 1/2 to 15 hours a week. And that's per press. I can't help but
think it's cheaper than running them. But does anyone remember all of the
debating during the gas crisis (pick any one in the last 30 years) about
whether it was cheaper to idle your car while in line for gas, or shut it
off and restart to move up?
"Mike Marlow" <[email protected]> wrote in message
news:[email protected]...
>
> "mark" <[email protected]> wrote in message
> news:[email protected]...
>> Greetings All,
>> I would like to show the actual dollar savings if we shut down machinery
>> at work during lunchtime. I know basic electric theory, but could use a
>> hand from someone with an industrial background.
>> Basically, no one is shutting down our punch presses during breaks. The
>> motors are 3 phase and either 220 or 440. I could find out the kilowatt
>> rates that we pay. What else do I need and how do I plug the numbers in
>> to come up with
>> a dollar amount for every hour that they let the motor run? I know that I
>> need the amperage from the motor nameplate.
>> I have seen electric questions here bring on a flood of both replies and
>> arguments, I don't want to see that happen. If the thread gets too
>> long, just let it die and we'll all keep to WWing........ Many thanks,
>> Mark
>>
>>
>>
>
> Oh Mark - you're biting off quite a piece here. There's more to it than
> the cost of the electricity to keep machines running., There's the cost
> of start/stop. On many machines, the hardest part of their lives is when
> they start/stop, The overall maintenance costs may well exceed any
> savings from shutting them down for a lunch hour.
>
> --
>
> -Mike-
> [email protected]
>
Robatoy <[email protected]> wrote in news:6eeea95d-d429-4021-bb82-
[email protected]:
> On Jan 20, 12:19 pm, [email protected] wrote:
>> You could suggest your employer install a motion detecting switch
>> (very inexpensve) in all neccesary rooms. We have them all around the
>> shop and office.
>
> I did this at my house.
>
>
Last time I did that for the light on the basement stairs, the motion
detector blew out within a week. Cheap BORG shit, I know, but now I and
everyone else have to reach behind the basement door to turn the light on
and off.
--
Best regards
Han
email address is invalid
"Owen Lawrence" <[email protected]> wrote in message
> Sorry, I'm not buying your logic.
>
> If the flywheel coasts to a stop during the break, it does so because of
> frictional losses. By leaving the motor on, the motor has to continuously
> overcome the losses that are always there. The motor is always doing work.
> If the flywheel coasts to a complete stop and sits idle for a time, then
> no more frictional losses are being incurred during that time. However
> leaving it on, the motor has to continue to do that work. The question
> becomes whether or not the integral of those losses is more or less than
> the work required to spin the flywheel back up to speed at the end of the
> break.
>
> - Owen -
I'm not buying anyone's logic on this. Power factor is going to come into
play tossing out the logic of both of you. The PF will be affected when
all the motors are started at the same time, thus affecting the rate for the
entire time.
Go take a look at the meter. Some have a pointer on a PF scale. I don't
know enough about it to give the definitive answer, but it does affect cost.
You could suggest your employer install a motion detecting switch
(very inexpensve) in all neccesary rooms. We have them all around the
shop and office. This would allow for every room in your building to
be dark when no activity is going on. You could perhaps sell it to
them as a savings of even more $$ on power as well as not slowing all
the employees down turning on and off lights. Forget about the times
the employees realize they forgot to shut the light and have to double
back a few feet to hit the switch.
One of my pet peeves, not directly related to this post, is when there
is resistance to increases in efficiency and moreover conservation.
Everyone conveniently ignores the first "R" in the three "R's" and
that is Reduce. Simple fact, global warming or not we all benefit from
increased efficiency and conservation. We get cars that go farther for
less $$, save money on fuel and power bills, often times get longer
product life, we do more with less which has been the capitalist
mantra for making money for all the ages. However now when
conservation is touted as beneficial, or god forbid mandated, the same
capitalists argue endlessly that we should be able to waste if we so
choose as no one should be able to infringe on our individual rights
(ACLU? zoikes!). I am a self employeed owner and operator of two small
business and I try to bleed all the savings I can out of "Reduce" and
efficiency and welcome any and all advancements in the area.
Mark
On Jan 20, 9:41=A0am, user <[email protected]> wrote:
> mark wrote:
> > Greetings All,
> > =A0I would like to show the actual dollar savings if we shut down machin=
ery at
> > work during lunchtime. I know basic electric theory, but could use a han=
d
> > from someone with an industrial background.
> > Basically, no one is shutting down our punch presses during breaks. The
> > motors are 3 phase and either 220 or 440. =A0I could find out the kilowa=
tt
> > rates that we pay. What else do I need and how do I plug the numbers in =
to
> > come up with
> > a dollar amount for every hour that they let the motor run? I know that =
I
> > need the amperage from the motor nameplate.
> > =A0I have seen electric questions here bring on a flood of both replies =
and
> > arguments, =A0I don't want to see that happen. =A0If the thread gets too=
long,
> > just let it die and we'll all keep to WWing........ =A0Many thanks, Mark=
>
> My employer wants me to shut off my 4 sets of 4 bulb florescent lites in
> my 8' X 10' lab office whenever I leave, even if just for a few minutes
> to speak with my workers!
> I'm in and out of my office all day long, plus my workers are in and out
> of my office when I'm not in there, so the lites get turned on and off a
> hundred times a day!
> I comply...it's *his* electric bill.- Hide quoted text -
>
> - Show quoted text -
On Sat, 19 Jan 2008 21:42:58 -0600, "mark" <[email protected]> wrote:
>What else do I need and how do I plug the numbers in to
>come up with
>a dollar amount for every hour that they let the motor run? I know that I
>need the amperage from the motor nameplate.
The problem you're going to face is that the dataplate amperage is
most likely the Full Load Amperage (FLA) of the motor. I'm assuming
that the motors are not under load - essentially idling - during the
break time. If that's the case, the amperage draw\ will be much less
than the FLA. For example, the 5HP motor on my cyclone has a dataplate
amperage of 20.8 amps. However under no load, the measured current is
less than 6 amps - less than 30% of the FLA.
Depending on accessibility and/or company safety policy, you might be
able to measure the actual amperages of the running motors using a
clamp ammeter. If not, the motor manufacturer might be willing to
provide the no load amperage specs for the motors. I don't know the
characteristics of the motors or their load condition during the
periods that concern you, but I believe it's a near certainty that
simply using the dataplate values will give wildly inaccurate results.
Tom Veatch
Wichita, KS
USA
mark wrote:
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery at
> work during lunchtime. I know basic electric theory, but could use a hand
> from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies and
> arguments, I don't want to see that happen. If the thread gets too long,
> just let it die and we'll all keep to WWing........ Many thanks, Mark
>
>
>
why are you giving the employees off for lunch? cant they eat a sandwich
while they're working ;-)
--
On Jan 20, 12:45=A0pm, "J. Clarke" <[email protected]> wrote:
<snip
> Reducing energy consumption doesn't always reduce costs you know.
> Every time you switch a fluorescent light on you shorten its life a
> bit. =A0Switching them on and off every five minutes is not cost
> effective, even if it does reduce your electric bill, because you end
> up buying more bulbs. =A0A long time ago the conventional wisdom was
> that if it's going to be off for less than half an hour then leave it
> on, but I don't know how the numbers work out today.
>
> Now, you're probably going to show me some link about start up power
> consumption being negligible, but start up power consumption is not
> the issue, the reduction in bulb life is.
<snip>
Agreed, thats why most good motion switches are adjustable delay. Most
data that I have read recently is calling out 15 minutes as the cutoff
for shutting off flourescent lights. Incandescents and Halogens should
be shutoff at all times theyre not needed. The switch waits the 15
minutes, then shuts off (or the time you set). If someone re-enters
the room in that 15 minutes the cycle starts over again. Either way,
its still reduction and efficiency through automation. Calculating an
accurate payback for the switches and their installation is very
situation specific but as in the originial posts, its no big deal to
start with the rooms/machines that idle the most, monitor usage
through monthly bills, and keep moving forward. Most operations have a
fairly consistant ambient consumption so any significant reductions
would show up readily.
Mark
"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
>
> "mark" wrote:
>> Basically, no one is shutting down our punch presses during breaks.
>
> The answer to your question lies in the application, namely punch presses.
>
> The motor is connected to a flywheel which stores energy to be delivered
> to the punch when the clutch is activated.
>
> When the punch is made, the flywheel slows down and delivers the energy to
> the punch to make the part.
>
> The balance of the cycle is used to bring the flywheel back to design RPM.
>
> As soon as that happens, the motor basically coasts consuming minimum
> power.
>
> So during your breaks, the press is basically operating at idle or minimum
> power consumption.
>
> If the press were to be shut off, the flywheel would coast to a stop
> losing all it's stored energy, then you would have to replace all that
> energy by bringing the flywheel up to speed before starting operations.
>
> This is a case where keeping the press running during breaks is probably
> the most cost effective operating procedure.
Sorry, I'm not buying your logic.
If the flywheel coasts to a stop during the break, it does so because of
frictional losses. By leaving the motor on, the motor has to continuously
overcome the losses that are always there. The motor is always doing work.
If the flywheel coasts to a complete stop and sits idle for a time, then no
more frictional losses are being incurred during that time. However leaving
it on, the motor has to continue to do that work. The question becomes
whether or not the integral of those losses is more or less than the work
required to spin the flywheel back up to speed at the end of the break.
- Owen -
Lumpy <[email protected]> wrote:
> Am I missing something here?
>
> MONDAY:
> 1159hrs - read meter
> 1200hrs - go to lunch, leave machines on.
> 1259hrs - return from lunch read meter
>
> TUESDAY:
> 1159hrs - read meter
> 1200hrs - go to lunch, turn machines off.
> 1259hrs - return from lunch, turn machines on, read meter
>
> Compare kwh readings
>
>
> Lumpy
>
> You were the Tidy Bowl Guy?
> Yes. I'm cleaning your bathroom bowl.
> www.LumpyVoice.com
If those numbers are real/accurate, it would indicate that the machinery
in question is actually pretty small stuff and thus an insignificant
part of the overal power usage. That small a KWH usage there wont' be
much difference period.
So, compared to the overall usage, whatever machines those are would
be insignificantly small enough to be negligible.
Twayne
Owen Lawrence wrote:
> "Lew Hodgett" <[email protected]> wrote in message
> news:[email protected]...
>>
>> "mark" wrote:
>>> Basically, no one is shutting down our punch presses during
>>> breaks.
>>
>> The answer to your question lies in the application, namely punch
>> presses.
>>
>> The motor is connected to a flywheel which stores energy to be
>> delivered to the punch when the clutch is activated.
>>
>> When the punch is made, the flywheel slows down and delivers the
>> energy to the punch to make the part.
>>
>> The balance of the cycle is used to bring the flywheel back to
>> design RPM.
>>
>> As soon as that happens, the motor basically coasts consuming
>> minimum
>> power.
>>
>> So during your breaks, the press is basically operating at idle or
>> minimum power consumption.
>>
>> If the press were to be shut off, the flywheel would coast to a
>> stop
>> losing all it's stored energy, then you would have to replace all
>> that energy by bringing the flywheel up to speed before starting
>> operations.
>>
>> This is a case where keeping the press running during breaks is
>> probably the most cost effective operating procedure.
>
> Sorry, I'm not buying your logic.
>
> If the flywheel coasts to a stop during the break, it does so
> because
> of frictional losses. By leaving the motor on, the motor has to
> continuously overcome the losses that are always there. The motor is
> always doing work. If the flywheel coasts to a complete stop and
> sits
> idle for a time, then no more frictional losses are being incurred
> during that time. However leaving it on, the motor has to continue
> to do that work. The question becomes whether or not the integral
> of
> those losses is more or less than the work required to spin the
> flywheel back up to speed at the end of the break.
This is not a question that you're going to answer by logic. You need
to measure the power consumed during the break, measure the power
consumed during start up, and compare the two. If it looks like
there's a saving, then you need to look at other factors, like the
effect of start/stop cycles on TBO.
What you need is a plan for measuring the consumption for each case,
and for each machine if they are of different kinds. Find out what
such measurements would cost and compare those costs to your best
guess as to the potential savings and see if it makes sense to do the
tests. If it does then your boss should be quite happy to go ahead
with them.
--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
mark wrote:
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery at
> work during lunchtime. I know basic electric theory, but could use a hand
> from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies and
> arguments, I don't want to see that happen. If the thread gets too long,
> just let it die and we'll all keep to WWing........ Many thanks, Mark
>
>
>
My employer wants me to shut off my 4 sets of 4 bulb florescent lites in
my 8' X 10' lab office whenever I leave, even if just for a few minutes
to speak with my workers!
I'm in and out of my office all day long, plus my workers are in and out
of my office when I'm not in there, so the lites get turned on and off a
hundred times a day!
I comply...it's *his* electric bill.
Lumpy wrote:
> Am I missing something here?
>
> MONDAY:
> 1159hrs - read meter
> 1200hrs - go to lunch, leave machines on.
> 1259hrs - return from lunch read meter
>
> TUESDAY:
> 1159hrs - read meter
> 1200hrs - go to lunch, turn machines off.
> 1259hrs - return from lunch, turn machines on, read meter
>
> Compare kwh readings
Yes, you are missing something. That method does not account for
other loads in the building.
--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
[email protected] wrote:
> You could suggest your employer install a motion detecting switch
> (very inexpensve) in all neccesary rooms. We have them all around
> the
> shop and office. This would allow for every room in your building to
> be dark when no activity is going on. You could perhaps sell it to
> them as a savings of even more $$ on power as well as not slowing
> all
> the employees down turning on and off lights. Forget about the times
> the employees realize they forgot to shut the light and have to
> double
> back a few feet to hit the switch.
>
> One of my pet peeves, not directly related to this post, is when
> there
> is resistance to increases in efficiency and moreover conservation.
> Everyone conveniently ignores the first "R" in the three "R's" and
> that is Reduce. Simple fact, global warming or not we all benefit
> from
> increased efficiency and conservation. We get cars that go farther
> for
> less $$, save money on fuel and power bills, often times get longer
> product life, we do more with less which has been the capitalist
> mantra for making money for all the ages. However now when
> conservation is touted as beneficial, or god forbid mandated, the
> same
> capitalists argue endlessly that we should be able to waste if we so
> choose as no one should be able to infringe on our individual rights
> (ACLU? zoikes!). I am a self employeed owner and operator of two
> small
> business and I try to bleed all the savings I can out of "Reduce"
> and
> efficiency and welcome any and all advancements in the area.
Reducing energy consumption doesn't always reduce costs you know.
Every time you switch a fluorescent light on you shorten its life a
bit. Switching them on and off every five minutes is not cost
effective, even if it does reduce your electric bill, because you end
up buying more bulbs. A long time ago the conventional wisdom was
that if it's going to be off for less than half an hour then leave it
on, but I don't know how the numbers work out today.
Now, you're probably going to show me some link about start up power
consumption being negligible, but start up power consumption is not
the issue, the reduction in bulb life is.
> Mark
>
> On Jan 20, 9:41 am, user <[email protected]> wrote:
>> mark wrote:
>>> Greetings All,
>>> I would like to show the actual dollar savings if we shut down
>>> machinery at work during lunchtime. I know basic electric theory,
>>> but could use a hand from someone with an industrial background.
>>> Basically, no one is shutting down our punch presses during
>>> breaks.
>>> The motors are 3 phase and either 220 or 440. I could find out the
>>> kilowatt rates that we pay. What else do I need and how do I plug
>>> the numbers in to come up with
>>> a dollar amount for every hour that they let the motor run? I know
>>> that I need the amperage from the motor nameplate.
>>> I have seen electric questions here bring on a flood of both
>>> replies and arguments, I don't want to see that happen. If the
>>> thread gets too long, just let it die and we'll all keep to
>>> WWing........ Many thanks, Mark
>>
>> My employer wants me to shut off my 4 sets of 4 bulb florescent
>> lites in my 8' X 10' lab office whenever I leave, even if just for
>> a
>> few minutes to speak with my workers!
>> I'm in and out of my office all day long, plus my workers are in
>> and
>> out of my office when I'm not in there, so the lites get turned on
>> and off a hundred times a day!
>> I comply...it's *his* electric bill.- Hide quoted text -
>>
>> - Show quoted text -
--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
Lumpy wrote:
> Lumpy wrote:
>>> Am I missing something here?
>>>
>>> MONDAY:
>>> 1159hrs - read meter
>>> 1200hrs - go to lunch, leave machines on.
>>> 1259hrs - return from lunch read meter
>>>
>>> TUESDAY:
>>> 1159hrs - read meter
>>> 1200hrs - go to lunch, turn machines off.
>>> 1259hrs - return from lunch, turn machines on, read meter
>>>
>>> Compare kwh readings
>
> J. Clarke:
>> Yes, you are missing something. That method does not account for
>> other loads in the building.
>
> Please explain what "other loads" will be
> mis-accounted when doing the comparison readings.
Since I have not seen the facility I have no idea. Since you have not
seen it you have no idea either.
--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)
If you can persuade management to cooperate in an experiment,
the simplest method is probably to check the meter while all the motors
are idling, then shut them off and check it again. By counting
the revolutions of the spinning disk in the meter during a fixed time (one
minute should be plenty) and using some arithmetic the power savings
can be calculated. Sometimes the necessary info is printed on the meter
itself, if not the utility co. can tell you what the conversion
factors are.
--
There is always an easy solution to every human problem -- neat,
plausible, and wrong." (H L Mencken)
Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org
In article <afc48f6a-c41a-4cea-bfe5-a54154d09eb0@e23g2000prf.googlegroups.com>,
<[email protected]> wrote:
>You could suggest your employer install a motion detecting switch
>(very inexpensve) in all neccesary rooms. We have them all around the
>shop and office. This would allow for every room in your building to
>be dark when no activity is going on. You could perhaps sell it to
>them as a savings of even more $$ on power as well as not slowing all
>the employees down turning on and off lights. Forget about the times
>the employees realize they forgot to shut the light and have to double
>back a few feet to hit the switch.
>
<...snipped...>
In some places I've seen (of course not MY shop :) ), this setup would
leave many employees sitting in the dark!
--
There is always an easy solution to every human problem -- neat,
plausible, and wrong." (H L Mencken)
Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org
In article <[email protected]>,
"mark" <[email protected]> wrote:
> Greetings All,
> I would like to show the actual dollar savings if we shut down machinery at
> work during lunchtime. I know basic electric theory, but could use a hand
> from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks. The
> motors are 3 phase and either 220 or 440. I could find out the kilowatt
> rates that we pay. What else do I need and how do I plug the numbers in to
> come up with
> a dollar amount for every hour that they let the motor run? I know that I
> need the amperage from the motor nameplate.
Given that this is (presumably) an industrial/commercial utility
account, the rates may well be more complicated than just $x per kWh
used, with adjustments or charges made for peak loads, power factors,
moon phases, and your deity of choice only knows what else.
That said, measuring the power consumption of a motor merely by the
faceplate rating (especially when said motor is presumably not actually
driving the equipment, but just idling at speed) is unlikely to be too
accurate. A motor's electrical consumption is, by applying the law of
conservation of energy, equal to the sum of the energy it puts
out--chiefly mechanical work and heat. Since the mechanical work is
rather insignificant in this case (again, assuming the attached
machinery isn't doing anything much), it's probably not a vast amount of
power being consumed. That's not to say it mightn't be worthwhile to
idle them during lunch, of course.
To measure it accurately, you really need to measure the current and
power factor. I'd venture to guess the power factor is pretty low in
this case.
(N.B. I'm not an electrician or anything related, so this may be
misleading or downright wrong. Caveat lector.)
--
Andrew Erickson
"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot
Edwin Pawlowski <[email protected]> wrote:
> "Leon" <[email protected]> wrote in message
>>
>> The really simplest and accurate answer is to simply shut the
>> machinery down as prescribed for an electrical billing period and
>> compare that bill to a same length period of not shutting the
>> machinery down.
>
> This is a USENET newsgroup. We don't want simple answers. We can
> stand simple answers. Please, don't confuse us with facts.
That's not very complex, whatever the two "simple" statements mean.
That is by far the most accurate way to asses it, including comparing
the numbers to last year's same period to see if usage is remaining
constant for the time of year involved.
Twayne
mark <[email protected]> wrote:
> Greetings All,
> I would like to show the actual dollar savings if we shut down
> machinery at work during lunchtime. I know basic electric theory, but
> could use a hand from someone with an industrial background.
> Basically, no one is shutting down our punch presses during breaks.
> The motors are 3 phase and either 220 or 440. I could find out the
> kilowatt rates that we pay. What else do I need and how do I plug the
> numbers in to come up with
> a dollar amount for every hour that they let the motor run? I know
> that I need the amperage from the motor nameplate.
> I have seen electric questions here bring on a flood of both replies
> and arguments, I don't want to see that happen. If the thread gets
> too long, just let it die and we'll all keep to WWing........ Many
> thanks, Mark
Some good responses here, but due to the problems associated with adding
measuring equipment and/or computations, it would probably be easier to
compare a billing cycle wiht idled machinery, assuming other uses remain
fairly constant for the test cycle and the preceding or post cycle. As
others have mentioned, with highly inductive motors and power factor
compensation banks, it pretty well means you can not just measure
current without knowing the relationship between it and the voltage
level; they are not in phase.
Another thing to check is whether or not there is a cycling "on"
procedure in use. I'm only familiar with one bldg using heavy current
draws but the equipment had to be energized in sets, not all at once, to
prevent large voltage drops to already running equipment.
You might do better with this question in one of the power groups, not
sure.
HTH
Twayne
"mark" <[email protected]> wrote in message
news:[email protected]...
> I'm kind of torn as to whether the restarting will draw more current than
> what is saved during the lunches. It only takes app 20 seconds to spool up
> the motor to a ready state, so I'm guessing that is more than offset by
> the 35 minutes it would be shut off. And additionally, there are also
> scrap chutes which are powered by separate motors. And we would be saving
> on the wear and tear by running at least 2 hours less 5 or 6 days a week.
> All totaled, the machines would run app 2 1/2 hours less per day (we run 2
> shifts), 12 1/2 to 15 hours a week. And that's per press. I can't help but
> think it's cheaper than running them. But does anyone remember all of the
> debating during the gas crisis (pick any one in the last 30 years) about
> whether it was cheaper to idle your car while in line for gas, or shut it
> off and restart to move up?
>
> "Mike Marlow" <[email protected]> wrote in message
> news:[email protected]...
>>
> Oh Mark - you're biting off quite a piece here. There's more to it than
>> the cost of the electricity to keep machines running., There's the cost
>> of start/stop. On many machines, the hardest part of their lives is when
>> they start/stop, The overall maintenance costs may well exceed any
>> savings from shutting them down for a lunch hour.
>>
You don't have to have good data in this case. All you have to have is the
"conservation" attitude and a loud voice to accuse your (former) employer of
despoiling the planet by leaving the lights on and the motors running. Such
issues do not require facts, except from those who would defend the status
quo.
If they decide to turn everything off, you can compare electric bills.
Maintenance is not a player, because you can always argue the failure would
have occured regardless.
<[email protected]> wrote in message
news:afc48f6a-c41a-4cea-bfe5-a54154d09eb0@e23g2000prf.googlegroups.com...
You could suggest your employer install a motion detecting switch
(very inexpensve) in all neccesary rooms. We have them all around the
shop and office. This would allow for every room in your building to
be dark when no activity is going on. You could perhaps sell it to
them as a savings of even more $$ on power as well as not slowing all
the employees down turning on and off lights. Forget about the times
the employees realize they forgot to shut the light and have to double
back a few feet to hit the switch.
The problem with the motion switches is that when some one walks into the
room the light coming on wakes you up.
In article <[email protected]>, "Lumpy" <[email protected]> wrote:
>Lump:
>> > Power consumption is power consumption.
>> > All other factors being equal, measure the
>> > consumption with the stuff shut down, vs
>> > the stuff running. The "other loads" are constant
>> > if you do the experiment correctly.
>
>Doug Miller:
>> Yes, except that "correctly" means
>> comparing long-term averages, not
>> two individual days as you suggested originally.
>
>Again, other factors don't figure in if the only
>variable is the machine on or off factor.
>
>January or August, night or day. The machines
>draw XX current. Do the experiment for two days
>or do it for 90 days and divide back to get single
>day figures.
Trouble is, you don't know what other loads might be in use elsewhere in the
building -- suppose one of the two days you decide to conduct your experiment
happens to be the same day that the welders are working through lunch on a
major rush project. That's certainly going to skew your meter readings. Taking
averages over a longer term is the only way to make sure that you've removed
normal day-to-day variation from the analysis.
Your sig is still malformed. It should be preceded by two hyphens, a blank,
and a newline, so that conforming newsreaders will recognize it and
automatically omit it when quoting.
--
Regards,
Doug Miller (alphageek at milmac dot com)
It's time to throw all their damned tea in the harbor again.