GF and CF on power strip

Is there any reason why I couldn’t put both the laser cutter and the Compact filter on the same power strip and power them both on at the same time using the power strip switch?

Your official recommendation here, being in problems and support, will be not to do it.

The :glowforge: has an internal surge suppressor, and plugging that into a power strip which has a surge suppressor of its own, makes both of them not reliable (I don’t know the math, but there were people talking about it early on) so really don’t. Plug at least the :glowforge: directly into the wall (I don’t know if the CF has an internal surge suppressor, but if you read the manual it’ll say in the safety section whether it needs to be plugged into a wall - which means it does - or if it can use a power strip)

Despite Glowforge’s ultra-conservative stance, there is no practical reason why this would be a problem. I’m no electrical engineer, but I know that surge suppressors are usually MOVs, which are devices that short out if the voltage gets too high, preventing it from reaching the protected equipment. People bring up this “don’t chain surge protectors” thing all the time, but I have never seen an explanation of what is supposed to go wrong or by what mechanism. I think it’s a superstition.

A more practical issue would be overloading the circuit, which isn’t going to happen from the Glowforge and Compact Filter alone. If you’re in the US, a typical residential circuit is 15A, which should be ok for up to 1440 watts continuous duty. According to the specs, the peak power draw of the GF is 800 watts (300W typical), and the filter is 350W. So even at peak, that’s only 1150W. If you also have a hair dryer or a toaster oven plugged into the same circuit, you might trip the breaker, but otherwise this seems unlikely to be a problem.

Of course, that’s just my opinion of the laws of physics, not the laws of interstate commerce and insurance liability.


I am (or was anyway…went to the dark side of software as a career instead :slight_smile: ). I’ve not bothered arguing because it’s not my monkey, not my circus. I do use a power strip. And, [shudder] I once had them daisy chained with an extension cord in between :wink:

This is far more likely the case. Or undersizing the cords. A lot of power strips are now rated for 13A, not 15A (same for a lot of light duty extension cords) and people do the Christmas Vacation thing all the time :slight_smile:

And most likely the reason.


I actually had a lecture from a guy sent out by the power company that actually recommended chaining surge suppressors! His explanation was that with say a lightning strike there is a micro-second delay before the suppressor clicks in and that in the time it takes for the power to go at least six feet the other suppressor can kick in. He also pointed out that from that point forward it is no longer a surge suppressor, though I am not sure how you could tell.

MOVs are installed in parallel inside many surge suppressors to increase energy handling capacity. There is no harm in running multiple strips in series, you’re just adding more varistors in parallel.

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That’s one big downside to MOVs. Get enough small spikes or one big one and they may no longer be any good. They also like to fail catastrophically, by starting on fire.

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I’ll take a page from @evansd2 and link to a previous discussion (which links to yet another previous discussion… does that count as daisy chaining?)

See previously:

Of course, if you’re just using a normal power strip I can’t see any reason why that would be a problem. And for me personally I’m using a UPS (Uninterrupted Power Supply), which has surge suppression, so :man_shrugging: But as jbmanning5 said, the official answer given in the past is plug straight into the wall every time.


Also not an electrical engineer, however my electrician is likely getting tired of hooking up industrial equipment in a residential home and answering random questions about why and how power and loads work.

My guess would for a Glowforge would be similar to the 2.2 kW spindle on my router. The motors are sensitive to sine wave distortion which surge protectors can create.

@drelleum it’s likely your UPS guide mentions not to use it for motorized devices. The APC UPS guide I have clearly stated this.

Connected equipment does not accept the step-approximated sine waveform from the Back-UPS. The output waveform is intended for computers and peripheral devices. It is not intended for use with motor driven equipment


I can say this; I experienced some odd behavior when plugged into an APC power conditioner. I thought it might be a good thing in the RV - it wasn’t.

The Glowforge is closer to a computer than a big AC motor.

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@dieterkutz: Aren’t you glad you asked! :sunglasses:

Our manual has direction on this topic, and, I can’t offer any help that runs counter to the usage in the manual. I am going to move this topic to the Beyond the Manual section of the forum so that you can continue to discuss this with others. Note that advice in this section is unsupported and is not reviewed by Glowforge.

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