Uninterruptible Power (UPS)

I'm posting this question on several forums, because it is important to know before I purchase equipment.

I'm wondering whether you concern yourself with power outages in your shop and on your router?

I have a UPS on just about every piece of electronics I own, but none of those gadgets consume the power of a router while carving. There doesn't seem to be much sense in only using a UPS on the electronics and not the router. (I can only imagine dragging a router bit around without spinning it.)

What do you do?

I do nothing. There isn't much you can do unless you run your shop on a generator. I don't believe it is worth it to buy a UPS that is large enough to handle full load current.

A typical Milwaukee 5625-20 3.5 HP router is about 15 amp. max @ 120 VAC that is 1800 VA.

A UPS is available in this power range (1500 VA to 2200 VA) for between $300 and $700 depending on brand and sales.

So it is technically possible to have a UPS hold the power to a router for those brief blips, and should hold it long enough for an orderly shutdown. Whatever that means with a CNC router!

Getting my first CNC router in the next week or so and I do plan to have a UPS on the computer and the 120v components. I have everything else on multiple UPS's in the house so I don't see much difference in this except I won't have one for the spindle and VFD. If we lose power while I'm cutting something and break a bit because the spindle stops then I'll just have to deal with that. Right or wrong I don't like electronics to stop abruptly because of power loss.

I've been running CNC since 1979 in a commercial aerospace machine shop. You can use a UPS to protect your computers, but if you loose power, bust an end mill and scrap the part, that's the the luck of the draw. At the speeds routers spin, and because you loose power on the axis drives too, most likely your end mill won't break in wood before it stops spinning.

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Originally Posted by David Falkner

Getting my first CNC router in the next week or so and I do plan to have a UPS on the computer and the 120v components. I have everything else on multiple UPS's in the house so I don't see much difference in this except I won't have one for the spindle and VFD. If we lose power while I'm cutting something and break a bit because the spindle stops then I'll just have to deal with that. Right or wrong I don't like electronics to stop abruptly because of power loss.

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On your CNC control box when you shut it down you just cut the power to it. The control computer is different as you use the shut down but the power still just stops.

On a long run job you will definitely want to have your CNC computer on a UPS so you can identify the line number in the program that the router stops on...otherwise you will have to start the job again from the beginning. I hope this makes sense.

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Originally Posted by Keith Outten

On a long run job you will definitely want to have your CNC computer on a UPS so you can identify the line number in the program that the router stops on...otherwise you will have to start the job again from the beginning. I hope this makes sense.

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I suspected that but haven't checked it out - thanks, Keith!

Some logical conclusions from the comments about UPS use:

• If you keep the computer alone running during a power outage, you can somehow recover the current location in the current toolpath.
• A UPS to operate your complete CNC router system would be overkill, because power outages mean the power is out for everything; including dust collection.

More?

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On a long run job you will definitely want to have your CNC computer on a UPS

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How often do you guys lose power??

The reason I brought this up is because I have a power "blip" at least once a day. A "blip" is hardly long enough for the BEEP to occur on the UPS.

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Originally Posted by Gerry Grzadzinski

How often do you guys lose power??

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A disruption in the power grid happens often here in my area. Not just my home but in several of the areas of companies that I worked for through the years in the Hampton Roads are of Virginia. Often it is just a blip as Paul mentioned but we can have a power outage that can last a couple hours on a sunny day. When storms are in the area I unplug my router and laser engraver due to the possibility of lighting strikes but its not worth losing several hours of work if the power blips or goes down for just a few minutes.

I live in one of the oldest areas of the country and as you would expect the power grid has some very old equipment and its been patched to death after decades of hurricanes and Nor-Easters. The population density also contributes to electrical problems not to mention vehicle wrecks when power polls are involved. The transformer on the power poll at the end of my street is unreliable and I expect the power company will not replace it until it permanently fails.

The ShopBot and CAMaster CNC Routers have software that show the lines of code when the routers are running. In the event of a power loss both programs will stop at the line in the code where the router stopped. You learn real quick how to restore a job just a few lines before the power outage occurs or curse up a storm when you have to start a long run over. Without a UPS the computer dies instantly and you lose the information.
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I believe the WinCNC controller uses a progress file that is repeatedly updated so that you can get back to the same place in the program as you were before after a power failure without a UPS. I don't know about other brands but suspect it may be a common feature.

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Originally Posted by Gerry Grzadzinski

How often do you guys lose power??

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Often. I used to say we're in a new neighborhood with a lot of construction with lines being cut often by contractors, but now the subdivision is 9 years old. So I'll change my story - we're in a 9 year old subdivision with lines being cut often by contractors. Also, it seems like when the weather gets bad or the winds are high we lose power, even if only a minute or two. All utilities in our subdivision are buried but the power lines feeding the subdivision are not buried. We've considered a 20 kW natural gas powered whole-house generator but just never have pulled that trigger. The UPS I'll put on our new CNC will be for the computer, not to try and run the machine.

I guess we are fortunate then.
My neighborhood is about 70 years old, with above ground power lines, and we may lose power for a few seconds only once or twice a year.