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Savings on powering down machines at lunch

kogmfg

Plastic
Joined
Mar 6, 2018
I’m looking for advice on wheather or not to power down 8-10 machine when everyone is at lunch. Trying to decide which is better. Less power consumption vs machine sitting idle with electric, lube oils and such just running.
 
Next time you idle machines, like for lunch, note kwhours on your electric meter, then read again when lunch is over. From your light bill you can determine the average cost per kilowatt hour.

Now compare this to the labor hours lost turning machines back on and waiting for controls to boot.

I bet I can guess the result.
 
Stagger the lunch break times, the half of the employees still at
the machines, can double up tending the other half, and then reverse
for the second half of lunch time.
 
You might want to do it half way. Shut off the motors and such but leave the computers running. What you may not want to do is shut off high precision machines and those that need to come to temperature such as molding presses.

Tom
 
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The plant I worked at had a peak usage meter installed by PG&E. Shutting down the machinery at lunch time was of course the best move, but on startup, machines were staggered so as not to peg the current inrush and incur higher costs. I think this is how it worked!

Stuart
 
So you want your guys to wait for the part to be finished running.. Take it out, shut the machine down, and
then go to lunch..

I'm all for a flexible lunch.. I would want them to wait 3 or 5 minutes for the machine to stop running, but
I wouldn't want them to shut it down, I'd want them to toss in another part, and then go to lunch.. Or go to
lunch early as soon as they tossed in another part...


Sounds to me like you are tripping over dollars trying to pick up nickels.
 
Tripping over dollars to save pennies.

I don't know you, but I do know you ar e wasting fuckloadss of money, but it ain't from running 10 machines for 30 minutes.

Bobw has the right idea. Run work through lunch, less deadtime.
 
If you want to save some nickels, run around during the lunch break and tag all the air leaks in the shop. Fix them as you can.

Compressed air is one of the least efficient, and most expensive, forms of energy in a machine shop. I work in a lot of shops and I usually work through lunch. When the machines are idle, the typical machine shop is filled with a continuous hissing sound.
 
I helped on a few energy audits at the previous job and if I recall the correct number for our area, one small air leak going 24/7 was supposed to be $1,000 in one year. One plant I helped at had over 600 hp of air compressors and we found close to 100 air leaks in one day. It would have paid that place to have one person full time keeping up with air leaks and the savings would have paid their wage and then some. I didn't get to finish that job out to see how it panned out, but best guess was they'd be able to turn off one of the 100 hp compressors and have it as a backup once all the leaks were taken care of.

When I am running my cnc router and get to a point where I am doing something else for a little while I will kill the vacuum pump and the air, then it is just the control and drives on. My machine doesn't have an easy way to power off the drives without killing the whole thing that I know of anyway so it gets left on. If I will be gone a couple hours I'll turn it all off.
 
Compressed air is a monster.
Have the guys turn out the lights when they go to lunch.
Fix your air leaks.
Fix the leaks in your building.

Make your guys eat at their benches.
 
Many electronic devices are less tolerant of frequent switching on and off rather than just being left on. You might save some electricity, but find that after some years there's an uptick in maintenance required.
 
Electronic stuff rarely goes bad when running, but shut it down and all kinds of bad things can happen. With 400+ machines in our facility, we found it much more cost effective over a weekend / holiday / long break to leave the machines on with E-stop pressed so that the lube pump / hydraulics / etc aren't running, but the control is on. When we were shutting machines off over the weekend we would often lose most of 2 shifts and sh$tloads of spare part money trying to get machines back to running. We don't shut machines off unless it is a have-to case. A card with a suspect capacitor can run for years, until you turn it off...
 
100% agree with tonytn.

Shutting down machinery for lunch is false economy. Electricity savings are tiny and even if nothing breaks earlier than it should even a 1 minute waiting time to boot up machines is going to cost you a lot more than the savings from electricity.

Not sure if turning off lights for lunch break is going to save anything either.
 
That must be the best idea ever. Especially if you work in a machine shop. Cutting oil ketchup anyone?

...or to quote a sign in the break room in one of our plants "this guy is having a bacon, tomato, and lead-dust sandwich"
.
 
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Yes !
The exact same thing happens with IT servers and most-any production machinery.

Heat kills stuff fast.
Dust kills stuff slowly.

Over 300+ hard drives (= servo amps on cnc machines), a temp. rise of 10C for a weekend due to air-con issues, would have 2-5 drives dead in 48 hours.
Exactly the same over 50+ servo amps on cnc machines - heat kills them.

But no-load drives and motors have near zero consumption - and generate near zero heat.
If I touch the case/back of servo amps or motors that are not moving, they are cool to the touch and the meter shows == 0 usage of power.
Say 20W for a 2.5 kW servo amp or VFD.
Usually the fans turn off, these days.



Electronic stuff rarely goes bad when running, but shut it down and all kinds of bad things can happen. With 400+ machines in our facility, we found it much more cost effective over a weekend / holiday / long break to leave the machines on with E-stop pressed so that the lube pump / hydraulics / etc aren't running, but the control is on. When we were shutting machines off over the weekend we would often lose most of 2 shifts and sh$tloads of spare part money trying to get machines back to running. We don't shut machines off unless it is a have-to case. A card with a suspect capacitor can run for years, until you turn it off...
 
Switch to LED lighting. The plant I work at switched to flourescents from sodium vapor lighting. and then only 5 years later switched to LEDS (high bay). Payback was supposed to be only 1 year.

In the shop the LEDs were inserted into the original fixtures.

Dave
 
I think shutting machines down for a 1/2 hour is asking for trouble with little to nothing in return.


Tell guys to shut machines before leaving for lunch...how many will decide to not load a part several minutes prior to lunch instead of letting cycle complete, then shut down and go to lunch.
-Expect to lose a few minutes before lunch.

When the Gents get back from lunch, then go hit the head..get to machine and turn on, then Home...
-Several more minutes lost.

You save a few cents in electric for that.
-Unless everyone turn on their machine at once spiking your demand meter...then you lose those pennies too.



I like my CNC's to cool down a bit before shutting them down. I have the guys leave them on before they head out for the evening. Hit E-stop, clear alarm and go. The fans draw the heat out of the electronics...I like to give them a good 10-15 minutes, then go around and shut them down.


What I like to see...gets close to lunch, toss a part or bar in and go. Let machines work while guys eat.

If machine cycle is critical or quick...hit the E-Stop, clear alarm, give hydraulics and motors a rest leaving electronics and fans on. Pretty darn close to off in power requirements.


But hey...different strokes for different folks.
 








 
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