Submitted 3 months ago by paf@jlai.lu to 3dprinting@lemmy.world
I’m looking to buy ups as I have few power outage where I live but I have never used one so don’t know what specs should I check for?
Ideally I will plug my 3d printer (about 100-160w when printing), a pi 4 with nvme drive (no idea of wattage) and a mini pc with n100 processor (around 10-20W)
Thanks for your advices
Please don’t confuse a generator with a ups. Ups isn’t meant to run devices for long periods. Generators are
Should have added in my post that power outage don’t last more than a few seconds so ups should be fine
Whatever would support the combined max wattage of the devices you will connect to it. Ideally something that can handle 50-100% more power. You can control some UPSes via USB or network, so you can hook it up to that mini pc or Pi (why are they separate?) and run NUT on it. You could technically pause a print/shut down a computer/Pi if an outage is more than x seconds to reduce power usage and get through one that you otherwise couldn’t.
“why are they separated”, not sure what you meant, mini pc is acting as a server for a few usage and pi is dedicated to klipper.
Yeah, that explains stuff. I thought you might have had some stuff on Pi that you could’ve been running on the PC. In that case I’d recommend that you run the NUT on RPi, and set it to pause print on a power failure, possibly change CPU scaling (i.e. to “powersave” CPU governor if you’re running Linux) on the mini PC, or even possibly shut it down in an event when the power outage lasts longer than a minute.
even though i think that the psu of the 3d printer might get you over the switching time offline usv’s have, i’d go with an online usv (voltage & freqency independent)
one missed step and your print might be gone.
depending on your outages you might go for a smaller battery, because you’ll have to replace them more often with an online usv.
First time I heard of online usv (also English isn’t my main language), will have to check this out
mine neither.
that’s why i wrote usv, it’s the german equivalent.
i meant online ups.
I can’t help much on the power draw side of this question, but one thing to look out for with a UPS is some sort of communication option. (Usually NUT over ethernet, but there are some USB options too.) Most modern UPS brands will have a plugin you can install on your Raspberry Pi and Mini PC that allows your UPS to signal, “Hey, I’ve got 3% of battery life, you actually need to gracefully shut down now.” It’s mostly useful for NAS applications with spinning drives, but it could help save your Pi’s SD card potentially.
It’s a pretty standard feature these days, but the cheapest of the cheap will omit it.
I have nvme setup on my pi 4 (I know it’s overkill for that purpose but already had pi setup like this prior to klipper), that being said I will definitely look at getting one with communication control even if power never goes down for more than a couple of seconds
The biggest issue is battery size: If the heatbed cools down the print fails. The heating is the part that takes the most power so the battery has to be large enough to support the entire remaining print duration or power outage.
Shouldn’t be an issue, power outage here are mostly about one second (5 at max) and even if my printer is being halted, my glass bed stick so much that my print don’t pop off by themselves, I always use a scraper even when completely cool down.
tal@lemmy.today 3 months ago
My experience has been that current UPSes tend to give a pretty limited runtime, more-limited than you might think, and are surprisingly-expensive for the capacity that they do provide.
The reason one historically really wanted a home UPS wasn’t necessarily to run a machine through a power outage, but to provide time to save any work and shut that machine down. We used to use filesystems that could become corrupt if they weren’t brought down cleanly. You could maybe run a machine for minutes, not many hours.
So it was important to warn (and maybe auto-shut down). UPSes are good at that. You have beeping alarms, software to auto-shut-down a machine cleanly when the battery gets low if someone isn’t around, software to notify a single attached computer about the battery level.
But with the combination of filesystems that don’t do that plus software that auto-saves, that’s less critical. What I think most people want is just more runtime, having a shot at making it through short power losses.
I think that today, if I wanted to provide longer-running resistance to power outages, I’d probably look at one of two things:
For a device or two, “power stations”. These sometimes get called “solar generators”, despite not generating anything. All-in-one box with batteries, charge controller, and inverter in one little case. This kind of thing. They won’t beep to warn you that the power is out, and they won’t have software (or interface) to tell a computer to automatically shut down.
For larger capacity, a “grid tie solar system”. These tend to be extensible, with 12V batteries or the like and separate boxes for the battery charge controller, and inverter. You don’t actually need to hook any solar panels or other power sources up to it (though, hey, maybe you decide that you want to do so).
I would look to see that the inverter in question provides “pure sine” output. Some inexpensive inverters provide a square wave, and some devices don’t much like this.
spedswir@lemmy.world 3 months ago
This is absolutely the correct information. I sold UPSs for years and the general consensus is that if you want more than 5 to 10 minutes of power, then you want to go with an actual generator solution
Saying that, UPSs tend to be used in industrial environments to keep machinery running until the generator starts up and can accept the load.
SzethFriendOfNimi@lemmy.world 3 months ago
And in the case of a 3d printer after so many seconds of now power what id use one for would be to cut off the bed and hotend, list the head and then run the part cooling fan full blast until power went out.
The print would be ruined but less likely to have heat creep and jams when the power goes out leaving the existing melted plastic to wick up into the heat break when the cooling fan goes out. And less likely, but technically possibly, the nozzle, still not sitting on one piece of plastic with enough heat to scorch or worse.
barsquid@lemmy.world 3 months ago
What sort of grid-tie systems are you thinking of?
I ask because I’ve been considering something like that and am finding nothing but things which have an internet connection back to the manufacturer. Some US states apparently prohibit charging batteries via the grid outside of certain scenarios. Abiding by that is fine, I’m not going to charge illegally. But I’d still like a device that is 100% not controlled remotely by some other party.
the_fourth@feddit.org 3 months ago
My Fronius Symo Gen 24 plus could run without a connection to the manufacturer and has local APIs for everything.
cmnybo@discuss.tchncs.de 3 months ago
Computers and 3D printers use switch mode power supplies. They don’t care if the inverter provides a square wave or a sine wave.
paf@jlai.lu 3 months ago
Yeah, I only care to keep the printer running for just a few seconds but thanks for the input