Two 120 volt inverters in series to make 240 volts
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- Опубліковано 5 лют 2023
- Testing out two EcoFlow delta pro inverters with their hub that connect them in series to make 240 volts, for powering bigger tools. I was expecting a bit of weirdness on this, but this worked better than I thought it would.
Thsi is not a sponsored video. I have had some disagreements with Eco flow, but not before they sent me those boxes. I figured I might as well make a not sponsored video about them. No money, but I can say whatever I want to.
I had this video up an hour ago, but with the audio messed up. This is a re-upload with the audio fixed.
Reupload?
Yes, audio was messed up, only half an hour's worth of views on the old one, so not so bad to re-upload
@@matthiasrandomstuff2221I will run video again to assign my view ^.^ If you took the trouble to reupload, so we should take trouble to help running this video with watch time and likes. Thank for your work!
... and re-watched! :)
@@matthiasrandomstuff2221 lol you had me checking my speaker wires
@@Mr.Beauregarde Wait until you find out about everybody in Europe has 3 phase 400V in house.
Whenever our power goes out, I’m always worried I won’t be able to run two circular saws in series if I need to. Glad to learn that it’s possible with these inverters!
😁
@@NormReitzel Gotta get ride of the "evidence" some how!
🤣
@@stevenspmd battery powered reciprocating saw and a few knives makes quick work of most ruminates and hogs. It just depends on how quickly you need to make sausage.
Maybe a 220 VAC well pump.
The device working as it should under stress is just as interesting as it not doing so. Thanks for stress-testing it, and for showing clearly what happens. Companies may not like when their stuff is pushed beyond its comfort zone, but they're just under-estimating their consumer's critical skills... If the message is: "don't connect sensitive electronics at the same time as starting up large universal motors or inductive loads", that's a useful message that doesn't really detract from the general value of the inverter. Not getting this message can lead to unintended carelessness and so does make the inverter less useful, however, so you're just doing everybody a favour.
Matthias: yeah it got some minor problems but overall it’s pretty good. Nothings perfect.
Eco Flow Engineering: We know, but these problems were outside the design basis anyway.
Subscribers: I’d still probably get one because I’ve seen it’s insides for free.
Eco Flow Marketing: Damn Mathias is making us look bad again.
You know you watched too much electroBOOM when you expect a spark at 2:38 😂
Two circular saws and these power sources would make a really brutal looking Segway.
This video conclusion reminds me of a huge problem the scientific community has in that it is really hard to get any interest in confirmation researches or getting published for not discovering something new.
Here you tested something, and got to the bottom of it. While there was no spectacular conclusion, it remains a valuable contribution.
Well done :)
There is this "why most published research is wrong", because novel and unexpected results are more likely to be published. And also more likely to be the result of errors.
It's funny that we're sort of expecting a "ECOFLOW EXPOSED" rant, but it turns out it's just a good, albeit expensive, battery inverter with known limitations. Obviously they didn't sponsor this video, but it ironically builds credibility in its own way.
yes, they got somethign for free there. mind you, I did get the battery boxes from them, though mostly I have them for "just in case"
They are really nat expensive when you compare to similiar products.
@@rkan2 The really are that expensive when you compare them to similar solutions, like a gas generator.
@@ewicky A gas generator is not a similar product and doesn't allow you to save your solar energy for later use for example. In other countries you can also get free electricity at times, again a gas generator wouldn't help. Compare to a Tesla powerwall or similar
@@rkan2 Ecoflow and similar products fall under the "portable generator" solution category. They are even marketed as "solar generators" and marketed towards traditional gas generator uses, like camping, power outages, etc. Where they get their fuel from is what makes "solar generators" so expensive. Solar panels and batteries are both much more expensive than gasoline and an engine, especially for intermittent use.
They don't offer grid-tie functions so it is entirely a different solution than Tesla Powerwall I realize the hardware is conceptually very similar, but entirely different solutions.
That was what every scientific endeavor should be like: form an hypothesis, test it and report your findings honestly, even if you hypothesis was wrong.
Great job, that was really enjoyable.
It was way more interesting than I thought it would be. Thanks for posting. Love that you tell it like it is.
Deja vu. Re-watching to the end to keep boosting the content
Same here. Surprised on how much I missed the first time.
I am not educated enough to understand most of this but somehow I still find it interesting and watch every single one. Thanks for making this video!
I think it's more interesting to see a product work as expected.
Thanks for all you're awesome content! I've learned alot in the past 8 years watching.
Still very interesting Matthias. Thanks for the awesome content!
I have learned a lot from you over the years.
Using the resistor across the blank clips gave me serious Electroboom vibes
Indeed, though I presume you caught 3:20? :)
I upvoted not for this video, but because of all you do on your channel. I would love if you posted more frequently.... please Experiment More!!! Keep up the great work
Im not electrically inclined or interested. But I like to watch you jabber on about it. lol The knowledge you have is amazing.
Always interesting Mathias. Continue to spread your interest and your curiosity. We always learned something. Merci. Be blessed. From Mirabel, Québec. ✨👍🏼❄️
Just like you, I blew up my Kill-A-Watt. I looked for burned traces and components and couldn't find anything. I hope you'd consider making a video on how to locate the fault and repair it. Thanks for your content. I really enjoy it.
It has an internal fuse, in series with the 100 ohm resistor going to one of the prongs. I just shorted the fuse -- super low amperage fuses are hard to find.
I know I'm not at your level but It was very interesting to me. Much appreciated!
At my previous job, we called these clip lead hookups "Suicide Cords" - I'm not self-destructive but you get the gist of it. Take care, sir! I value your insight!
I also have a power cord with just clip leads on the end. only recently did it occur to me to wrap electrical tape around them so they wouldn't short if they touched accidentally!
Mathias, with children around, that's not a very good idea...
"...I'm not going to do that since my name is not Mehdi..." Nice reference but there were some BOOM worthy electro based setups there. You had me cringing with some of them. It's always fascinating watching your videos.
i was waiting for some sudden sparks and explosions like ElectroBOOM
Matthias is testing how far can you push a battery before having to put down battery fire :D :D :D love the experimenting
LiFePo4 would be the only kind of high density battery this size I'd let into my house and have a good night sleeping.
Agreed. I'll take the extra weight for peace of mind.
I have the ecoflow river and it has a bunch of odd behaviour. It went back to them once, but it came back with the same problems and was told it's normal. Still nice to have with the power goes out though.
Dang that's a lot of trust in a guard. And leaning over a running table saw.
I have this weird mistrust of circ saws after I let go of one once and the switch failed closed. Luckily I didn't get injured, but the saw got an amputation as a result.
generally, the heavier and more solid a table saw is, the safer it is.
I cannot understand why EcoFlow got angry with Matthias.
In a country not far from Canada, where the microwaves have a label stating that you shouldn’t dry your pet inside of them and everyone can have an AR-15, I would say they the info “do not connect sensitive electronics” would save EcoFlow from sues.
I would get one EcoFlow if I would have the need. I think it’s a great piece of equipment.
Matthias, I think you maybe mistaken about that high frequency oscillation during over current. I think what is happen is that the device goes into over current protection and stops gating the output FETs. When the FETS stop switching suddenly you’re left with a resonant tank that’s oscillating that’s created by the output inductors and capacitors. The actual return to normal signal after the ringing is the device recovering from the over current condition.
how is this different from what I explained?
@@matthiasrandomstuff2221 I interpreted your explanation as the high-frequency ringing = the device trying to restart after hitting current limit.
You cut me off when I was halfway through watching the first one you posted!
Me too.
sorry. Last time I needed to re-upload, I made it unlisted, but then the old video kept on getting views after that. So I decided I needed to use the hammer this time.
Super interesting, thank you sir.
"They work as they should." Review done!
I kept waiting for a boom.
Great video
They should have added a soft start feature that could be user toggled. If such feature were implemented the surge current instability would be reduced substantially, if not elimiated outright for high current inductive loads.
Even if they are upset with you, lets hope they understand this is constructive criticism and you're only trying to help them make a superior product.
That "strange" power issues has me wanting to measure the THD (harmonic distortion) of my non inverter generator. I tried connecting the power brick (just the power brick) for my Bluetti to my generator and measured the voltage/ripple using an oscilloscope, oddly, it didn't seem much different when compared to being connected to mains. About 100mV ripple for both, even when connecting an additional 1500W heater as an extra load. The total power output of the generator is about 3200W.
Would love to see this test done with an inverter gas generator. I believe they have voltage on the neutral as well.
Probably very similar since the difference is the power source, basically from a large battery to a small engine DC dynamo. I plan on making my own hybrid inverter generator by taking an automotive alternator and combining it with a small gasoline engine, an inverter and an auto battery.
@@WJCTechymanGas generators don't have dynamos. Efficiency would be piss poor, not to mention the issues with brushes...
I use a neutral bonding plug on my inverter generator without problems. I do this in order to utilize an RV surge protector. The surge protector trips power off without neutral and ground bonded. If there were voltage on the neutral, I believe the inverter protection circuit would trip when the bonding plug was installed.
Seems like these things would be so much better if they just included a secondary transformer that had a proper center tap for a real ground (and neutral) reference with 220v from hot to hot. Would have saved a lot of wiring headaches. And would likely smooth out the waveform under heavy loads too
It would of course increase cost some as well as weight
and would add 10 kg of weight, cost a lot, and made the device consume considerably more current on idling. And that's why they don't do that.
The EG4 6K Off-Grid Split Phase Inverter is a low frequency 120V/240V inverter with a heavy transformer inside. My understanding is that this inverter is well suited for starting inductive loads like table saws. Would you please consider doing a video on this inverter? Also any comments you might have about this inverter would be helpful. Much thanks.
I don't have one of those inverters. And if I did, I wouldn't have anything to power it off of.
Commenting to boost engagement for the re-upload.
The table saw start/stop switch seems dangerous. If power is lost it should trip the button to off state.
That freaked me out. 😱
Never a problem when working alone
This is called a no volt release and is standard on modern equipment. Active rcd/gfci plugs also have this functionality .
Cool stuff, I wish I understood it all, but interesting nonetheless 💕🙏👍
What’s inside the bridge box?
The Electroboom joke got me ;) haha
.. quite interesting being halfway through the original upload when it went unlisted then private..UA-cam app was very confused!
You mad scientist you!
There's a lot of suicide wires going on there. Suggest to run both circular saws through a slab of wood using one hand each while juggling a running electric chainsaw with your feet like Lionel Messi. I'd wear at least non-conductive gloves while hovering around those exposed wires. My hat goes off to this electrical expert. Thanks for making the video and stay safe!
240v fun with both channels of audio. 🤯
its not an issue with the different HZ?
Are these in series or have 2 120v legs 180 degrees out of phase? That would be our normal power
in the US.The box seems like it puts the 2 phases output for 240v phase to phase.
is "neutral" floating in reference to the DC Side? an is DC input GND the Same as PE GND?
Can someone connect two of these in parallel and they sync wave forms or may something go 💥?
Interesting
I always wondered about these things
I used to be off grid running off solar and generator to fill in
Never had courage to try one
I would have had to find one I could recharge in 5 to 8 hours
Can you get 480v from two of the European version??
In addition to the "hardware protection circuit", could the phenomenon you've uncovered have contributions from satruated transfomer cores producing non-60Hz weakly damped harmonic oscillations? Could this be fixed with an external reactive power supply (capacitance), placed immediately prior to load, to address this hypothesized, low-volatage induced in-rush current from an inductive load that is a significant percentage of the inverter's capacity?
Any way to "diy" a decent soft-start adapter cord for situations like this? I know there is stuff you can do with capacitors, but I've only seen that done with induction motors, not the universal-type motors in some power tools.
There are soft start modules that work like a dimmer for light bulbs but those increase voltage automatically, some taking up to 5 seconds to reach full speed.
Some power tools incorporate them to avoid tripping breakers and to avoid overloading portable/small generators on construction sites, they also have the side effect of extending the life of the motor and gears that suffer much less impact than with an instant start.
There are some aftermarket modules available online, some have 2 wires and are connected in series with live or neutral, others have 3 wires, one for neutral, one for live in and other for live out, but they don't care if you. wire them with reverse polarity like live, neutral in and neutral out...
Those are the most common aftermarket modules, altough a lot of tools made in China have those fitted from factory:
KRRQD20A
T0601001
KR-009
XS-12/D3
LQD-2A
Brand tools sometimes have it built into the switch or some module that performs additional functions, such as overload prevention.
A "soft starter" for an induction motor would have to be some sort of VFD (variable frequency drive), quite expensive. For universal motors, it's much more doable, and many tools with universal motors already have a soft start.
@@matthiasrandomstuff2221 There are ones bases on SCRs that are cheaper than a VFD.
@@matthiasrandomstuff2221 library.e.abb.com/public/bea0ee02a2a84683ada4daab569a1cb2/1SFC132392M0201_Performance_comparison_between_2-_and_3-phase_controlled%20softstarters_rev2.pdf
Definitely got enough backup power to survive the recent polar vortex. Did your mini splits hold up?
We turned them off when it hit -20. It was a good chance to burn scrap wood in the wood fired boiler in the house, kept the house warm at -29 c
@@matthiasrandomstuff2221 A wood stove is a good backup especially if the power goes out. Power did go out here (in Moncton) for about 4 hours, just enough time for me to think about pulling out the generator and then the power came back on.
@@matthiasrandomstuff2221 wood fired boiler? I'm jealous
The neutral-to-ground problem is probably because the floating ground is building up some static charge while the inverter is running. So, if you connect it you're providing a huge over-voltage for a brief moment that could damage the inverter.
I showed with the 48kohm resistor that it wasn't entirely floating, probably half a megohm between ground and the inverter, which is more than enough to absorb any static before it can cause harm
@@matthiasrandomstuff2221 Huh. Well, I'd wonder because this problem could be very bad if there's a way to float the ground internally.
@@matthiasrandomstuff2221 I remember people talking about problems like ground loops and static buildup and all kinds of floating issues with mis-matched grounds. I'll bet the control feedback system in there hates it.
You had a disagreement with the manufacturer?!?...no one saw that one coming 😂😂😂
This is an ElectroBOOM episode waiting to happen.
I hope not. I don't want to break those battery power stations
What was the disagreement with them?
I wonder if there's a way to have that control algorithm simulate a voltage sag. So that instead of simply killing the output it reduces the output voltage until the power draw equals the maximum current, and then if some amount of time passes (maybe .2 seconds or 10 cycles or something) with the voltage below 120 spec then it kills the output as the sine wave passes the 0 point.
Yes, they do let the voltage sag a bit -- not as much as they should though
wow this is over my head
Waiting for you to do random experiments like this on an f150 lightening. Matthias would certainly find some random way to use a power tool that would freak the truck out.
I don't have such a truck, so won't happen.
Can you do a review on these Pro Power Save. Guess you plug it into the wall and it saves you on electric bill? I seen adds for them.
Big Clive and others have covered these scam devices numerous times before. The "real" ones are just capacitors and are said to improve your overall power factor. They'll only be successful if your overall load is inductive. And home users aren't charged for power factor so the savings are zero in any case.
any thoughts around running these in a 12v grid with solarpanels? Like in a offgrid cabin. How are these compared to regular batterys?
Why 12 volts? These can take and output 12 volts, but they are natively not 12 volt devices.
Matt, I dunno; I thought the video was interesting. Also, if you did not show up on the video I would say that by looking at your test connection setup, you could have been Mehdi BUT I didn't see any sparks or hear any crackles or screams! Cheers!
The EVSE does a lot of double checking and the car before it charges. I wonder what really happened there.
Did you answer why the overhead lamps are all zig zag pattern in your shop instead of in a strait line? Is it for shadow mitigation?
yes, I didn't want them parallel with the edges of the furniture
Was I noticing lots of crossover distortion?
This video was way less random then the eye exam
Good video--I've been interested in these units. But, at some points I honestly wondered if you were probing and connecting exposed mains voltage wires so cavalierly just to troll safety ninnies and drive audience engagement...and I guess I commented, so there you go.
mostly out of expedience. Heavy duty clip leads are a good thing to have.
Those inverter designs; once you can get into the MCU, or whatever is controlling the sine wave switching of the I guess IGBT's in the H-Bridge, seems like when the two are connected something is switched to phase sync the two. The logic seems super easy. Like basically you can literally just use one of the units, let's say, MCU's H-bridge switching control to control both the systems H-bridges to create the sine wave. I've been reading into a little when I get the time, as I'd like to be able to make better use of the Prius inverter-converter for making a more versatile generator, welder and plasma cutter into time. Those definitely have the IGBT's and other systems that can be aquired cost effectively since they last and no one needs to buy one. Sure beats being shredded and more energy and mass wasted to recycle. I was thinking would really clean up the brushless-asynchronous alternators (generators) from whatever source like the Prius MG or other say crappy brushless designs that are the older makes models without the inverter. Would also clean up the synchronous sine wave on the older non-inverter generators that look worse than I realized. Jason Wallace did a great video showing the signals from the three designs, mains, synchronous and pure since wave inverter sources.
Save your your Kill-A-Watt meter, over voltage is just the regular fuse needs replaced and over current will need the thermal fuse replaced. I even made a video documenting my repair from an over voltage situation on a crappy 1200W 2-stroke brushless generator.
I've also wondered about adding some sort of slow or fast start capacitor extension cord box add on for the motors needing the surge starting current. I've wondered also about adding an inductor... though those don't really store the power like a capacitor (or bank) does.
Wonder if you can gang two of the 240V Euro models together to create a 480V monster!?!?
And for conclusion - Ecoflow is still great inverters with great build quality.. 😉 But power meter needs to be investigated next.. 😂
Try to connect some smps power brick or phone charger to Ecoflow and then run circular saw..
Deeper investigation will be nice..
Anyway, excellent video, as always! 👍
IMHO Most SMPS devices would not care about this oscillations, because they just rectify the voltage and then run DC/DC step down conversion. All small ones do that. Bigger ones have PFC that may change a bit.
@@anonanonkiewicz1921 You can't guarantee that.. All depends from topology, input filters in smps and load on them when anomaly occurs. First may go bridge rectifier from overload or just fuse.. Same damage at mains use, sometimes, is even caused by bad connection.
And when bridge is gone, other parts from input stage may be damaged. Only output don't care about these spikes but smps will be dead!
@@artursmihelsons415 as far as I remember, the spikes didnt have any higher amplitude, just the frequency (looked like about 1kHz). Why would that destroy a brigde rectifier? If the frequency is too high for the diodes, they dont care, so does the capacitor.
we need @electroboom to test how hard they kick ;-)
A problem shared is a problem halved!
My planer runs on 400v threephase. How many inverters do I need?
The motor is 400/690 wired in Delta, so I think i will need twelve.
One three phase inverter
nice configuration , tel them if they could connect three of them to get three phase generator .
Much more efficirny to have a 3-legged H-bridge type arrangement to make 3 phase than 3 separate inverters.
Yeah, universal motors have an enormous current draw on startup. They're essentially a dead short.
the reason why they cant do 240V "US style" is because the 240V system is differently set up with a center tap for 120V and without that you lose the 120V option. and a 240V model cant switch between 120 and 240. the inverter would be stupid inefficient or just have half power at 120V.
Would that work for a 240v welder?
Why I just love our 240 VAC (and the three phase 380 VAC). No fuzz...
I don't think that two cycles of harmonics is bad (1/30th) second given that the starting current is essentially limited only by the resistance of the wire, at least instantaneously.
its a lot more than 2 cycles
Can you recommend a soft starter that would work with a table saw like yours? Much thanks
You would have to get a VFD drive, quite expensive. That's the only way to soft start an induction motor
@@matthiasrandomstuff2221 Great idea! Thank you sir. I work as a factory electrician so use VFDs when given 3 phase power to begin with and the motors are 3 phase induction. I didn't know there existed VFDs that take 240V single phase as input and produce 240V single phase as output. If I understand correctly this type of VFD is something that I can purchase to run a single phase 240V table saw. Is that correct? Much thanks for the information your videos provide.
Why make it so you need two boxes for 240vac rather than just one?
I have several guesses.
1) Lower cost for those that only want 120vac, as it cost more to put two inverters into one box so that you can have 120 and 240 in one box, than one box that only does 120vac.
2) probably the bigger factor is the kinds of loads (central air conditioner, laundry dryer, electric stove) one might run on 240vac would be too much for the battery in one box.
Most inverters do a lot better if the high draw motors have a soft start circuit on them.
Contractors trying to get their work done quickly HATE this idea.
2:15 First you have normal oranges, then you have flat oranges ... It's just like magic!
How do those high frequencies pass through the final LC filters?
The filters are barely big enough. Under extreme loads, probably the filter inductor saturates, making it less effective.
@@matthiasrandomstuff2221I guess that's why LF inverters are still popular. Heavy as hell, but an inductive load master.
You should review movies. Idk might as well try ❤️
Question: Can you buy an aftermarket inverter that will clean up the output of a regular generator? I have a 10kw portable generator that runs my house in a power outage, but I'd like to plug an inverter of anywhere between 500 watts to 2000 watts in to one of my AC outlets and have it produce a pure sine wave for my computer equipment....any ideas? Thoughts? Inventions?
That's a power conditioning UPS, iirc
Yes you can. I have a Apc 2200ah double conversion ups that does exactly that. It is always in invert mode and always supplies 120v 60c. I bought mine cheap used. Not for motors though.
@@philarmishaw3730 I've considered that, but consider this, an inverter generator doesn't have batteries. So I'm still curious, can you get just an inverter that will go from 120 to 120 and clean up the power....
It has to have batteries because it needs to draw power from them to make up for voltage brownouts
@@philarmishaw3730 Are you suggesting that a gas powered inverter generator has batteries?
How do you have a HP meter? I didn't know they made meters. Are they good or cheap?
I won that back around 1995 for writing an application note for HP. It might be a re-branded fluke.
I should add, this was before Agilent was spun out of HP.
As I said before, being an inverter designer myself, this kind of instability is difficult to remove in HF inverter designs. For power motors, use a LF inverter (about twice the weight).
only twice the weight?
@@matthiasrandomstuff2221 Yeah, maybe 3-6 times! :) But if you need stable waveform power that can handle very high overloads for a while, it's the ONLY solution because it has low output impedance, so it strongly resists all the crap and distortion you saw on your scope.
BTW - I have tried various direct sine wave tracking & regulation to try and mitigate this, and many others have tried as well, but the low impedance part is ONLY possible if you have FULL push/pull output control, whic although not that hard to do, is VERY hard to make blow up proof. As Piles of blown mosfets in my workshop attest to this. The control loop complexities are somewhat extreme, and since 99.999% of inverter users only care about price, there is not much incentive to built such units. So like I said, LF is the only PRACTICAL solution for now.
Why do 120v plugs have 2 prongs and 240v have 3..?
120 volt plugs with a ground also have 3
@@matthiasrandomstuff2221 oh I just assumed 3 prongs was only a European/British thing
not series, it just makes two 120v phases which is 240v. that is all 220/240v is in your north American home. Their combiner is really meant to input into a camper or generator input panel to your breaker box.
it makes 240 volts by connecting them in series, effectively, with the middle as neutral or ground
Matthias, I don't see you ever having a successful sponsor relationship. You should buy your own items and evaluate/trash them mercilessly. It would probably boost your ratings too.
it might, but financially too expensive. Yotube ads don't pay that much, that's why all the big youtubers have sponsors.
@@matthiasrandomstuff2221 Hey I have it. You could *threaten* to review products unless they paid up.
Two 60 volt floating phases is exactly how 120v outlets are wired on cruise and cargo ships. There is no ground rod on a ship, obviously.
you cold jus the the ship hull for a very excellent ground
Two saws, one fuse.
I kept expecting some bad hand move to be sparks. Hard to watch lol 😆
Connecting a scope probe to AC is a bad idea. Scopes are grounded. The neutral is tied to the ground remotely (at the panel) so there is a voltage drop on the neutral. If you ground the neutral through your scope its possible to damage the scope. For this test the battery inverter source does not have this problem. I use a special probe for this purpose that has safety ratings similar to volt meters. Nice video.
And I used a power station that wasn't hooked up to ground. that scope probe was the only ground connection the battery box had.
@@matthiasrandomstuff2221 I'm just worried about someone doing this in there garage and blowing up the scope.