Power protection for glowforge

In the setup manual it says do NOT connect the GF to a power strip or APC UPS battery unit… My concern is having an expensive machine plugged directly into the outlet and no protection. Why does it say to not have a protective surge protector?

Short of unplugging every time, and praying nothing spikes while using it… how are we supposed to safeguard our gf?

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Glowforge has stated that the machine is already surge protected. The reason they do not want these units inline is that the surge protectors and battery backups can change the power waveform and may cause problems with the laser. I have mine on an APC surge protector because I am paranoid and haven’t had a problem with it, other than some trolls trying to convince me that just the act of plugging the GF into the surge protector would instantly immolate them both.


Thats my concern… it can have protection inside, but if it gets hit, what happens? A storm can damage, even a careless worker can cause a hit… Its great they have something inside to protect it… but the question is - if it gets hit, what happens? Does the GF get damaged and we need to send it back since there is no user service parts? Does GF guarantee it against spikes? There seems to be many unanswered questions about this. Can someone from GF company state in plain english what the policy is and how we keep the equipment safe? And more importantly, what happens if a spike hits our GF? Telling us to plug it right into the outlet seems very odd…

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I am not speaking for Glowforge.

At a previous job, I insisted that surge protectors not be plugged into other surge protectors or battery backups. After I left, the remaining IT staff decided that, without me around to enforce such a silly rule, they could just go ahead and do that. They had a pretty bad fire a couple months later. The fire fighters held up the daisy-chained surge protectors as the likely culprit.

So, it’s totally fine … until it isn’t.

In any case, OSHA and NEC recommend against it.



A surge protector plugged into a surge protector can cause an electrical fire. The two surge protectors trying to regulate the power can cause one to have catastrophic failure (i.e. fire and damaged electronics).

Years ago, I had a coworker’s surge strip catch on fire and melt the cords to the surge strip (and left a huge scorch mark on the carpet and back of metal desk). The fire department scolded him for daisy chaining his surge strips, as this was the cause.

Nearly 20 percent of all failures and fires stemming from surge protectors happen as a result of daisy chains, according to a publication by the U.S. Office of Compliance (http://www.compliance.gov/publications/fast-facts/power-strips-and-dangerous-daisy-chains).

And you are not supposed to plug laser printers and copiers into standard surge strips, because they can cause the surge circuit to trigger when they start a print job, drawing more power, which can cause a brownout to the printer and other electronics plugged into the strip.

Lastly, even if your Glowforge didn’t have surge suppression built in, most surge protectors aren’t rated to handle a single device that draws more than 15 amps, which is what the Glowforge does. (you are supposed to plug the Glowforge into a 20 amp outlet. It doesn’t have to be dedicated outlet, just an outlet on a 20 amp circuit).


Really glad you posted this. I’ve had mine plugged into a UPS battery for a year now and I guess I didn’t see a warning against it. I would also like to know (as you asked) what happens if a surge does hit the Glowforge? Is that a trip back to the factory?
I had squirrels chew through and disconnect the ground line to my entire house a few years ago, and (I later learned) a previous owner had incorrectly installed the physical ground bar so… everything started grounding out through the cable line. Perfect storm, I know. Anyway, the only things in the house that didn’t get fried were the things on surge protectors (which died saving the expensive stuff; heroes!)
Extreme example to illustrate why I have quality surge protectors on everything (and never daisy chained). I’ll reread the manual now and likely take the GF off the battery UPS to comply; but I’m uneasy…
Thanks to everyone posting with such good information!
Hey, does anyone understand how whole-house surge protectors factor into all this?

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Just for the sake of accuracy, I’ve never seen this recommendation. The recommendation is to plug it directly into a wall outlet on a circuit with 800 watts available.

A 15-amp/120v circuit can provide up to 1800 watts.

A 20-amp/120v circuit can provide up to 2400 watts.

The Glowforge uses a max of 6.66 amps on a 120v system.


It has been my understanding, based on previous posts, that UPS units with true sine wave output were fine to be upstream or at the very least “tested”.

My impression has been that more than a few of us were running on such devices.


Sorry. Looking way back in the forums, it was recommended in a Q&A discussion to have a 15 amp dedicated circuit or 20 amp circuit shared with other devices if you were running a Glowforge with the air filter, since both together were pulling over 1400 watts.

This was from a discussion before pre-release units were in the wild so I don’t know if the current version of the air filter has increased or decreased the total wattage.

My issue and concern is not daisy chaining … but instead the fact the GF has this built in… so if/when a power issue strikes, it does not kill my $100 power strip… but instead it kills my $4000 glowforge…

It doesnt make sense to have this in the GF… if it gets hit, your GF is dead till its internal unit gets fixed (which I assume means sending it back $$$)

Wouldnt it be more efficient and easier and less cost to secure it via an external $100 unit?

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My GF is in my man cave (converted garage)and I installed a dedicated 20 AMP circuit for the GF and the computer. Just seemed easier than taking any chances with a power strip or UPS.

It’s been stated before - it’s your machine and you can do what you want with it.

Keep in mind that if you need actual GF support, you will need to remove from the power strip and go from there.

The Glowforge team gets a fair amount of support tickets - and they can’t test every single users install and set up scenario. They need to establish a baseline install with what they know works best. If you deviate from those guidelines, then you need to get back within those guidelines to get official support for problems that could be related to the install part that is not within the guidelines.

I.e., my material is not cutting all the way through; remove it from the power strip and do the troubleshooting

I.e, my exhaust isn’t venting correctly with a 20 ft run and a booster fan; revert to recommended set up or get support from community members in Beyond the Manual.

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then why not have the power protection unit OUTSIDE the GF as an included item? Having it built inside it seems odd… cause when it gets hit by a power strike, then we need to send back the entire unit since its stated its not a user serviceable item.

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I don’t have the answers you want - and the answers you want aren’t going to change the official recommendation that exists in the Users Manual.

Why not this, or why not that, isn’t going to change your unit that is built, or change the units that are going to be built, going forward.

Sorry if that sounds curt, but I’m not sure what you’re after. If it’s permission to use a power strip/UPS/surge protector, the answer you’re going to get is that the manual contains the recommended installation. It’s your machine to do what you want to do with - if you want a surge protector on it, by all means, do it.

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I don’t, but I have one installed at the breaker box, so I have no choice. Same was true with the pre-release unit. Both have functioned perfectly.


But you would be daisy chaining two surge suppression systems. I know you are thinking of people daisy chaining two surge strips so they end up with double the plugs, but that is only one instance. In the case you are talking about, you have one surge suppression filter in the surge strip and one in the Glowforge, so you have two surge systems daisy chained together. And supposedly the one in the GF is better than what most surge strips will have.

The fire in my office that I mentioned earlier wasn’t because my co-worker had 11 items pugged into the two surge strips. My co-worker had connected two surge strips together so the 2nd one was within range of his laptop and monitor cords. (I think he had a calculator plugged into the last one too), but there was nothing but the 2nd strip plugged into the first.

The two surge systems will end up confusing each other causing you to loose the protection you want. When you turn on the GF, it’s going to trigger the surge suppression in the strip, which will trigger the surge suppression in the GF.

If you want to try an experiment, try hooking a UPS into a surge strip and only plug a desktop computer into the UPS. Start the desktop computer. You will hear the UPS clicking on and off a few times because the surge strip is confusing the UPS’s own protection system.

There are sure suppression systems built into copiers and most laser printers too. (not the really cheap laser printers). They build them internally to keep the average user from not using it. If the average user can remove it, they will, so build it internally.

The first thing Glowforge support asks when troubleshooting is if you have your equipment plugged into a surge strip or extension cord and if so, to remove them.

There have been a few reports of weird behavior with surge strips (this was someone who had the GF plugged into a cheap 6 outlet expansion plug) Weird behavior at start-up (new GF)? and one person whose Glowforge died and it was suspected it was due to an issue with the UPS it was plugged into.

And this post from Dan: Don't use a UPS? He says they have only successfully used the Glowforge with $2,000 UPS. He also said if there is an electrical related damages to the laser, the GF warranty will not cover repairs if your device was plugged into a UPS or surge strip.

You’ve seen this in the manual and had several people tell you similar information, but it appears you are determined to add one, so I’ll finish with this — it’s your device and you can do whatever you want to it, but don’t get upset if Glowforge won’t honor the warranty if something happens.


i will also say this. most of the “surge suppressors” you buy will handle a little flux, but something big will likely blow through them and fry your equipment anyway. a $20 (retail) piece of plastic with a little breaker in there isn’t really all that much protection. there’s a reason they don’t cost very much. they’re really just giant multiplug extension cords. some of them have those big “warranties” on them, but i’m sure they have lots of legalese built into them for their protection and they put them out there knowing few will actually try to collect.

I would really like to know the mechanism behind the “Surge protectors catch fire when daisy-chained” claim. The only thing I can find, after almost 6 hours of searching, is the same reason you don’t daisy chain power strips - the strip and surge protector is rated for a certain current draw, and when you daisy chain them the capability is reduced.
I am an engineer with a decent grasp of surge protection systems and no one has been able to explain this mechanism to me. There are lots of anecdotal data points saying it happens. I have yet to have anyone explain why.
I know that there are a lot of recommendations against it; every one I have read states that it is due to overload - too many things can be plugged in. This doesn’t seem to be what you are reporting. Can you play any light on the why of this?

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“Daisy-chaining” is not a problem. As the power systems guy for five states’ worth of interstate pipeline, some of my stations have multiple levels of surge protection - at the 15kV, level, at the 480-volt level, at the 120/240 level (in the power panel) and at the receptacle (power strips) and much of industrial 120- volt powered equipment has built-in surge protection.

A failure of that protection due to an adverse interaction would do more than kill a $4000 printer.

Overload? A surge arrestor in good condition presents NO load other than the indicator light found on some units. If your arrestor gets warm, you need to replace it, or you MIGHT be exceeding its ratings. If you’re not sure about the whole volts-amps-watts thing ask an expert.


I think having different steps is different.
Now, I trust the government about as far as I can throw my congressman, but the guy up there ( @jeffarazzi) did post this: