Hi everyone, I need a UPS for my X1C to cope with the continuous power cuts. My doubt is about the type of UPS, pure sine wave or modified wave? As we know, some components with active PFC require pure sine wave otherwise you risk burning them. I don’t know if the X1C requires a UPS with pure wave, I’ve seen some users on various forums who power it with cheap modified wave UPS, but before buying one I would like to hear some of your opinions. My X1C is 220v 1000W, so I will probably need at least 1500VA or better a 2200VA.
Thanks
I have four UPS in my office. The one I trust the most is this one from CyberPower. I would not get hung up on brand. Any reputable brand such as APC, CyberPower and such will be good enough. You are correct in being concerned about Sinewave output. I had to discuss my needs with a CyberPower tech support engineer when I noticed odd issues with my 1000w Gaming PCs. It was he who stated that the non Sinewave models such as my model EC850LCD were not designed for switch power supplies.
But before you go spending all that money. Buy a cheap power meter first to ensure you understand your power needs. CyberPower and APC have power calculators on their website but there is no substitute for doing your own measurements. Here’s a recent topic on Power consumption with some recommendations for cheap power meters. X1C Drying mode and power consumption - #3 by Olias
2 Likes
I have 3 UPS “APC SMT1500IC” (pure sine wave) at home, and I have already tested the consumption of the X1C on these UPS, being 1500VA when the printer heats the bed the maximum load admissible by the UPS is reached (about 1000w) … so the 1500VA is fine but better to choose a 2200VA. The real question is do I get a pure sine wave UPS or not? Because a 2200VA pure sine wave costs much more than a modified sine wave UPS, if the X1C does not have a switching power supply I can save by buying a cheap UPS. Unfortunately I do not know the characteristics of the printer, so I wanted some opinions perhaps from those who have already tested. What UPS do you use for the X1C?
1 Like
What modified sine wave actually is is an approximation of a sine wave using discrete voltage steps. The modified sine wave looks like stairs on an escalator from the side.
Modified sine waves carry lots of harmonics from the abrupt changes in voltage during an AC cycle. Those harmonics can cause radio frequency emissions, interference, and other nastiness. Switching power supplies can usually deal with modified sine waves but it’s hard on them.
The link below from TrippLite explains it a little. Something I didn’t realize is the modified sine wave only is present when on backup power. Some UPS designs always run the outputs from the battery and have a separate circuit that charges the battery from the line. Those don’t have switchover glitches that can trip up connected equipment so can be another desirable feature.
A modified sine wave output will either have glitches in the switchover or will always be hard on connected equipment. Pure sine wave is much lower noise and easier on what you connect. Modified sine wave is cheaper and appropriate for some loads but not appropriate for others.
Just noticed about the X1C power supply - just about guaranteed to be a switcher. Linear supplies are big, heavy, and waste a fair amount of power. I can’t say it’s a switcher for certain, but pretty sure it is.
2 Likes
So in short the X1C will work fine with a modified sine wave UPS but is it better to use a pure sine wave UPS?
I don’t know and can’t say for certain that an X1C will be fine running on modified sine wave.
According to TrippLite, modified sine wave can cause heating and result in inefficiencies which translates to using more power. It all depends on the power supply the printer is using and how much margin it has and how much it needs. Those are unknowns.
Please don’t take this as saying your printer will be fine running modified sine wave. Whichever UPS company you are looking at will possibly/probably have a warranty for protected equipment. If you are still looking at modified sine wave, I’d read that carefully and maybe even check with their support people. They might have more insight.
But also check the Bambu warranty. Some things may invalidate it (I didn’t read it closely). You’ll maybe want to know where any liability is for going with a modified sine wave. No idea how much of this even matters but it’s the considerations I could come up with as possible trouble spots.
Why even bother with those obsolete 12v SLA UPS’s? Their days are over. It’s a false economy. Get one of the LifePO4 generator’s, and you’re golden for even a long blackout–and you won’t have to be messing around with the short run-time and changing the batteries of the typical SLA. And, of course, get the pure sine-wave. Prices on LifePO4 have fallen like a rock in the last 6 months, and so prices on the generators have also fallen. If you haven’t looked in the last year, give it another look.
1 Like
That’s what I use, @NeverDie - an Ecoflow in my case. I hear Bluetti are also good.
And on these devices, avoid Li-ion (Li-Co) like the plague. LiFePO4 is much safer and has a significantly longer lifetime. It also tolerates many more charge/discharge cycles.
1 Like
Exactly. Something like that. I had a VigorPool laying around since before I bought my X1C. At the time I chose it over others only because it was wifi instead of bluetooth, it had the phone app, and because it constantly runs the AC off the batteries, so there is no 10ms or 20ms transition time. It’s 0ms. A classic double conversion topology. Be that as it may, I’m sure there are even better and cheaper choices now. I’ve been running my X1C off it since the beginning, and no issues. None. Ever.
Or build your own. It’s easy. You can choose best-in-class components–EVA cells, top notch BMS, super-high-quality inverter (higher efficiency means less heat, which means less fan noise)–and you’re future proof if you ever want to upgrade it. You can buy 4 100ah cells now for as little as $100, including delivery to your door! Seriously. It’s crazy how low the prices have dropped. But if DIY isn’t your thing, then go for a commercial package. You give up flexibility, but you get instant results: plug it in and it just works.
But if you wanted to go cheap, you could get 20ah cells. You’d still outperform the APC shown above. I bought 4x 32ah cells in May for $47, delivered. More than ample for a router UPS, which runs off DC, so I won’t need an AC inverter and I won’t suffer those conversion loses either. You can buy 4x 20ah cells for probably $30ish dollars, delivered. It’s not the sweet spot as far as ah/$, but it’s so cheap it’s a “who cares?” trade-off.
1 Like
Yes, the X1C uses a switching power supply for the electronics, motors and fans. The heated bed is driven directly from mains and is the highest load in the printer.
Resistive loads like the heated bed are completely insensitive to the sine wave accuracy. Resistive loads will work well even using pure DC.
Switching power supplies should not be sensitive to input waveform either, because they convert the mains AC to very roughly filtered DC through a simple bridge rectifier. The switching power supply then switches that roughly-filtered DC voltage rapidly to make finely-regulated and well-filtered lower voltages used within the printer. Whether the rough DC is rectified from pure or modified sine wave supply is immaterial.
Your electric utility prefers than all the loads you power draw current consistently in relation to the instantaneous voltage of the sine wave. This means they prefer you draw maximum current at sine wave peak and proportionately less current as the sine wave slopes up or down. Large AC motors - like in your air conditioning unit or well pump - behave in this manner and that’s what the power utilities are designed to drive.
Loads using bridge rectifiers do not necessarily draw current proportionally and this can cause some problems for the utility provider. If all loads were bridge rectifiers and there were no large motors, the utility would have to design their generating equipment and distribution networks very differently.
So switching power supplies can and do cause issues for the electrical utility. But higher-quality power supplies are Power Factor Corrected, to minimize problems to the utility. I believe the power supplies in the Bambu X1C are PFC types, which makes things a bit easier on the power utility. None of this makes any difference to you as the power consumer.
In my opinion, you shouldn’t waste mental gymnastics regarding this issue. Modified sine wave UPSes work perfectly well with switching power supplies. There is no significant downsides to using a modified sine wave UPS with switching power supplies. There is no danger to the UPS or the load and it doesn’t affect longevity.
I run my two X1C units off a modified sine wave UPS from Tripp-Lite. If you can find a pure sine wave UPS at the same price, go for it. But if it’s $20 more expensive, it’s not worth the extra money.
Just use the modified sine wave UPS and it will work just as well for this application.
2 Likes
Thanks for your post. It’s good to read other, different opinions on the matter, especially when they are knowledgably informed and backed by experience, such as yours.
Which one specifically?
I haven’t tried Tripp-Lite. I’ve tried a number of APC and Cyberpower UPS’s in the past, including one commercial grade Cyberpower unit, and was surprised that the electronics in a number of them failed at < 5 years, including the expensive commercial grade one. Out of warranty, out of luck. These were units that were manufactured far more recently than the well known Chinese capacitor debacle, so at least that much can be ruled out. Nor have I had extreme power surges that might account for it. Maybe Tripp-Lite does a better job of it, but those experiences left me not wanting to invest in at least those particular brands or UPS designs again.
You gave a compelling analysis in favor of modified sine wave. If it were me, I’d probably still hesitate, but for a different reason: if I ever wanted to re-task the UPS to something else, it may or may not be a satisfactory match, whereas a pure sinewave won’t be an issue.
Again, thank you for your thoughtful post!
1 Like
If the X1C power supply is with active PFC, a UPS with pure sine wave is required. Power supplies with active PFC require a pure wave, at least this is the theory that you read on any forum or site, then if the printer also works with a modified wave, great 
1 Like
Good to know, but I don’t think we know any details on the printer power supply. Might be wrong, though. From a photo I saw it looked like a switcher since it obviously wasn’t a linear but no idea if it has PFC or not. My -guess- is it doesn’t since that adds parts and expense but who knows?
Either way, I wouldn’t run a 3D printer on modified sine wave. It could be fine but one of the features of my UPS is true sine wave output so I don’t have to bother. As another user pointed out, “heaters don’t care”. But other parts do. 
I’ve been burned on false economies enough that I try to do things the better way even if it costs more. Been caught pants-down before. That’s just my approach.
The datasheet lists a number of standards it conforms to and that could be key to knowing if they do PFC. I’m not familiar with the standards to be able to say.
I guess I should say I don’t have an electrical degree. I do however spend my days getting paid to test audio equipment for defects.
I have a small APC UPC for the time being that isn’t sine wave. For backup it’s kicked in once and lasted almost long enough to get me through the outage. Just shy but thankfully resume helped. I’ve never noticed any issue with power on my P1S. I have a 24v power tap running my lights and bento box and still nothing close to a hiccup. Printer is fine, as is it’s power supply.
I run my TV, Dennon, game systems, DVD on either a Panamax or Furman Line conditioner. The Panamax hums along. The Furman has tripped twice, what I suppose was a surge but nothing scary. All electronics are on the same circuit.
I also have several electronics running in the bedroom on just a decent surge protector. Never have had an issue there either. All devices are in like new condition.
My point is I don’t think it matters really. I have the two line converters because I got them very very cheap from where I work. One of the perks. The idea that one would need perfect clean power has been seperating audiophiles (and I guess me, lol) from their money for years. Unless you’re stealing power from the poles or have a few hampters spinning wheels for your fridge, you’d be fine with our without an APC.
If anything this thread has saved me money. I had a new UPC loaded into my cart then I realized it’s not needed. Printer get’s power and it loves it, works just fine. If power goes out what am I going to do let it run until it comes back, where it will resume as if it never went out. So…
As for surge and dips, yeah it can keep it running. I’m 54 years old and I’ve had that happen once with no damage and no irritation.
Just my 2 cents. Save your money. If you must get something just get something to click on and off real quick if you get a rare dip. If you live in one of those places with very dirty power…I dunno, move?
Edit: DO have a surge protector. A good, or better yet high quality one. Lightning doesn’t care, at all. Lost a somewhat good Sony AV receiver once due to lightning. Had moved some stuff and couldn’t reach the surge protector, lazy to move it thought it could wait. It didn’t.
1 Like
Possibly consider that if you’re doing long prints (possibly multiple days long), then in a longer power outage the bed will lose heat, your print may detach from the bed after cooling down (as you would normally hope that it would), and then it’s game over. You can always start over, but power resume in that kind of scenario isn’t going to help you. If you’re not awake or otherwise not around to notice or shut shut it down, you’ll be facing sphagetti, or worse, when you return.
1 Like
Very true. Whattya gonna do?
I’d need a monster for a long print. If it’s close to the end, well you just gotta laugh.
In the end, I’ll keep a UPS on it, but only for a “what if” occasion.
The point I was trying to convey about the 100ah LifePO4 battery is that you can withstand a pretty long power outage, and your Bambu will sail right through it. Your Bambu doesn’t actually draw all that much power except when first heating up the heat bed, and even then on the 110v Bambu, not all that much (a peak of around 350w, and then it drops pretty quickly from there). You can of course get less, but 100ah is a very common capacity for a lot of these systems.
1 Like
Yes, and I failed to mention I won’t spend that on a UPC for the rare occsasions I may find myself in. Sorry. I get it though and don’t disagree with you.
Just not a value for me I guess.