Maybe they should just improve their product to make it more resiliant, rather than blaming customers for thinking that 148 V is below 150 V? Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer.
And no matter what happens, customer support should help the customer, not blame them.
This is 100% on the manufacturer if they intentionally chose to highlight the "best case" 150V, rather than the 120V lower end. Especially without any additional safety mechanisms.
The article presents it oddly, it's not that the converter maximum input gets lower, it's the solar panel output that gets higher from the nominal quoted value (which is not a maximum, and not really intended to be used as such). Derating your converter is equivalent for the purposes of ensuring margins, but it implies the issue is in the wrong place.
I believe the vendor here produces both the device and the panels being plugged into it, and while they also supply other vendors' panels, they seem concerned primarily with customers who buy all components from them and then experience this failure.
I agree the labeling is an issue here, but the solution must come from the wider industry or regulatory bodies; the alternative is for vendors to switch to their own pseudo-units to internalize the math, which would not be good for customers either - think "ACME Generator2000 accepts up to 4 Power Units of input; each ACME SuperEco Panel supplies 1 Power Unit, or 1.5 Power Units if you're in Canada...".
Saving users from having to do a little thinking to not brick their device is a tried-and-true excuse for vendor lock-in in our industry :).
There's hiding complexity, and then there's creating fake reality for people.
As it is, panels are gonna produce variable power depending on the weather. Putting interoperability with third-party panels aside, to get the simplicity of "max 2 panels in series", they'd have to either cap the max power on the panel/generator link and dump the excess, or set the limit based on the worst case a customer is likely to encounter. I.e. they're either gonna waste power, or gouge their customers for extra hardware. Neither of that makes sense for an ecological product sold to a price-conscious customer base :).
> Not everybody buying these has a Ph.D. in physics and if it says 148 V on the label and 150 V on the other label then it's your product that has a problem, not the customer.
Idk. I don't have a PHD, but 220V sounds like 240V to me. I wouldn't do this.
I feel like getting advice about how to wire up electronics should not be so hard.
> Maybe they should just improve their product to make it more resiliant
Adding "resilience" usually adds to the per-unit cost. I think making a web page adds some cost too, but at least that can be amortised.
> And no matter what happens, customer support should help the customer, not blame them.
I think that's happening here: Making a web page to educate future customers seems like a really good idea. I wouldn't have thought that necessary until I saw it, but I'm always excited to learn something new.
The existing customers who did dumb should consider this a relatively cheap education in electronics; cheaper than a PHD at least!
Also, whether the company also gave them rebates or credits we don't know here, but telling "customer support" they "should help the customer" is also telling them they're not helping the customer, and you don't know that.
They're just being cheap. If you're going to let customers plug panels directly into your box you should have overvoltage protection. It's that simple.
> Making a web page to educate future customers seems like a really good idea
I don't think this is an official website of ecoflow.
Other than that I agree. I don't think asking for a bit of knowledge from the customers is a bad thing. A warning in the manual about safety factors should be enough.
Considering the electric code has an 80% rule for loads, anyone assuming they can use 100% of what is on a label probably should not be doing electrical work.
I agree with you, but. The NEC has an 80% rule for continuous loads (over 3 hours) that use a typical circuit breaker as overcurrent protection. If you use fuses or a 100% rated breaker as your over current protection, then you can use all of the available ampacity. Anyways, devices that use a 15A receptacle (for example) will not draw more than 12A continuous if they’re meant to run continuously (3 hours or longer).
This feels a bit like the logic behind "do not put hamster in microwave" warning labels.
I think if you work with electrical or electronic systems in practice, you learn pretty quickly to respect tolerances and that data sheets are a map, not the territory.
Also, electrical installations are usually seen as a field that should be done by trained personnel, not arbitrary laymen home owners. So I think the appropriate reaction would be to remind people that they should hire an electrician to do the installation, if they don't have the necessary specialized knowledge themselves.
Actually if "you work with electrical or electronic systems in practice" you get pissed off at everything for how dumb it all is: 12V DC batteries are more like 14 nominal? AC wall plugs dip voltage when printers turn on, random equipment you arent even sure in the building can trigger UPSes based on unknown settings in the device? International standards and communication protocols mean nothing as "a standard" because each company has their own entire list of bugs/implementation mistakes. All the international enforcement certifications care way too much about inconsequential bullshit and miss all the true showstopping problems in most industries?
This world is amazing anything runs at all. The slightest addition of complexity is causing everything to fail now.
Modern computers are less reliable than ever, some companies have decided to REMOVE the pinhole bios reset (that has been around for 30 years) at the same time as things are buggier now and dont boot again until you physically unplug the bios battery deep inside and hard to get to.
So on the one hand we have a product which isn't even remotely designed for the use case (hamsters), and during normal use shows obvious behaviour (cooking) that should imply risk to said hamsters. On the other side, we have a product designed to be installed in an electrical system, and shows no signs during normal use that it's installed unsafely, and where the advertised specs are not actually safe for normal usage.
Whether or not the company in this case shares some or most of the blame with novice users - the analogy is not a great one.
I have the impression these are consumer products so I would them to be designed to be installed by people who do not normally work with electrical systems. If they are only sold to tradesmen that would be different.
I don’t know about the components they’re selling, but with electronic components, it’s on the buyer to properly read the data sheet and understand what the quoted nominal specs mean.
Unless it’s safety critical, you usually don’t want a system with a bunch of active electronics to prevent someone wiring it up wrong, because those components will interfere with whatever you’re hooking it up to, such as the MPPT, the battery, or whatever else.
This is like how AA batteries have a nominal voltage of 1.5V but the actual open circuit voltage is 0.9V~1.65V depending on charge level, temperature, etc. If you connect an AA to something that’ll explode at a voltage of 1.55V, that’s on you.
Similarly if you buy a 470 ohm resistor, you will find in on the data sheet that’s usually at 20°C. To know what it’ll be at any other temperature, you’ll need to use the temperature coefficient to calculate it.
In your AA batteries analogy, this is like saying that you do not need to state that the device exploding at 1.55V would do so, not about battery declarations (panels in this case).
This isn’t electronic components, this is sold as a consumer level gadget that anyone can use. No one expects a standard consumer to understand data sheets like that.
You started off by saying you don’t know about the components they’re selling - but that turns out to be absolutely critical to understanding the context here.
Either way, I can’t believe they just let it fry the main board instead of having a sacrificial fuse or equivalent go first in these scenarios, whether it was a product aimed at professionals or not. It’s just dumb.
Maybe it would be a good idea to at least add a pair of MOSFETs (one for each rail, + and -) and a voltage meter? Like, the voltage doesn't rise to maximum instantaneously, there should be ample of time to detect voltage rising to a critical amount.
So say, the input is rated for 150V, spec the components to sustain 180V, and trigger the MOSFETs to disconnect the panels at > 160V.
And maybe also add a big ass buffer capacitor, that can be used to soak up a bit more energy in the case of an inrush spike before the MOSFETs actually disconnect.
MosFET's or IGBTs are likely what failed. And, capacitance is something you do not want on a string of PV.
DC starts getting really nasty to deal with somewhere between 36-52v, with 150v of panels not being something joe-blow should be able to buy on amazon. Designing these systems to be safe is difficult.
Why doesn't this just produce a shutdown? Inverters have to track voltage and current on the input and outputs sides, and can turn themselves off. They shouldn't be that close to the absolute maximum voltage ratings on the components.
Too much current is a heat dissipation problem, and you've got some time to deal with that, at least tens of milliseconds.
Anyone have a teardown on these things? Are they using under-rated MOSFETs? That's all too common in solid state relays from China.
High voltage, low RDSON FETs are (slightly) more expensive, and these products are cheap. A better design would use a higher-voltage rated input switch with poor (slow) switching performance, like an IGBT. Don’t design critical infrastructure around EcoFlow hardware.
Fujitsu, which sells MOSFETs for this application, writes: "Firstly devices should be rated at 600V or 650V, as this will generally provide more than adequate protection against the threat of high voltage transients."[1] That's a nice big safety margin. It should hold until the voltage monitoring shuts the whole thing off.
Not seeing UL certification on this thing.
If we're going to have US protectionism against China, a good first step would be to require UL-type testing, carried out in the US, on all imported electrical devices that run on more than 12VDC or contain a battery chemistry capable of thermal runaway. Electrical safety is a solved problem if you can keep people from cheating.
> They shouldn't be that close to the absolute maximum voltage ratings on the components.
This appears to be a situation where the engineering team determined the absolute maximum input voltage and the marketing/product people put that number straight into the documentation.
Standard practice with electronic parts is to determine the absolute maximum rating, then to specify a recommended maximum that allows for some safety margin and variation.
Instead, this company determined the absolute maximum and then just shipped it.
One way or another, many of us are in agreement the company screwed up and it’s on them to fix it - whether that’s their marketing, their manual, their lack of over voltage protection, whatever it is it’s their fault.
Yet so many people in this thread are so keen to blame the customer, it’s pure ego from them. “I’m too smart for that to happen, so it’s all their fault!” they sneer. Classic bad faith forum behaviour…
> Plugging in four 400w solar panels in series is similar to filling your gasoline powered car with diesel and wondering why the car manufacturer isn't replacing your new car.
I don’t think this analogy works. The solar input works like Diesel or Gasoline in different temperature. It’s pretty unreasonable to assume the consumer knows when depending on temperature unless the explicitly state in the manual (I’m willing to bet good money majority of the people in US have never read their car manual either)
Around the skiing season, many automotive magazines will remind diesel drivers to buy “winter diesel” or use additives if e.g. driving up to the Alps or similar cold places.
Straight Vegetable Oil (SVO) diesel conversions do. It'll gel at low temperatures, so they blend or switch to a separate tank of regular (or bio) diesel while the engine is cold, wait until it generates enough heat, circulate that heat along the SVO lines and into the tank, then switch over. Then switch back a few minutes before shutdown so the lines are full of regular diesel for the next cold start.
Because they run their engines well within the margins of their design. If you were running at the edge of the envelope you would find that the temperature does matter.
I'm not sure I know what a good analogy looks like. If the two things are identical, then the analogy is uninformative. If they're at all different, you will zero in on the differences rather than the similarities.
Sometimes they can be ok pedagogical tools, but they're easily misused as tools of persuasion.
I was going to comment on the manufacturer's safety margins, but then I found a graph [1] on the variability of voltage vs temperature and it seems to be a lot steeper than I thought/expected, to the point that I'm wondering how these do not require either training or a voltage regulator to install and operate properly:
Basically anything that consumes solar power incorporates what's called a "MPPT", or maximum power point tracker.
Basically, it's a smart DC-DC converter that continually tracks the voltage/current output of a solar panel and adjusts the load to extract the maximum available power from the panel.
It's not uncommon to have issues with extremely high panel voltages in snowy climates, when they're first illuminated in the morning. If you are close to the maximum voltage your MPPT charger can handle in normal circumstances, extreme cold can even damage things during the initial morning transient. You then have to do oddball things like use a crowbar system to prevent blowing up your MPPT system.
Another post commented but that’s exactly the point of the MPPT. Not only is it temperature dependent but solar incidence angle matters too (how the sun angle is relative to the surface). MPPT works by changing the internal impedance to match the ideal charging voltage. But there’s a limit to how much it can regulate but I think it’s very fair that a consumer would expect nominal voltage times panels in series is less than the marketed solar input to work.
There's a reason people don't install electric equipment without training.
This is just like not upsizing wire gauge if you have a bunch that are loaded simultaneously buried together in a somewhat insulating wall.
Without the burying under plaster, everything would be fine.
But combine that with simultaneous loading during summer, and you fry/roast the PVC insulation.
The part that they are warning about burning out is a voltage regulator.
Those things are normally built to handle a nominal 115 V assembly of panels. There's probably something on the manual about this, but when you put a giant label saying your device supports 150V, people are not going to read the manual.
Sounds to me like someone is misrepresenting their products. A solar panel's VoC should be its maximum possible output in ideal conditions (open circuit). If that's under your product's maximum input voltage, it should be no problem. Ever.
Is EcoFlow advertising a higher input voltage than their products can actually take, assuming most people won't actually reach it due to temperature inefficiencies? That'd be false marketing, and it'd make this article manipulative, false blaming of the customer.
STC ("standard testing conditions" for solar panels) is 25C so if it's freezing 0C you have 25 multiplied by 0.33 Volt = 8.25 Volt more than STC in open circuit situation.
Unfortunately inverter manufacturers seldom document how many Volt will destroy the MPPT and up to how many Volt the MPPT will safely turn off by itself before breaking.
Not to mention a fail-safe MPPT would/should just crowbar the input if there's any potential for overvoltage.
Solar panels are current sources that waste their power into a long string of silicon PIN diodes that eventually reach their forward voltage and begin to eat up all that juicy current.
You can just take the current and keep the voltage as low as you want, just make sure to take all the current or it's voltage will rise to let the diodes take the current you aren't using.
> A solar panel's VoC should be its maximum possible output in ideal conditions (open circuit)
I think this is where the confusion arises - what do you mean by ideal conditions? Ideal conditions for solar generation are not necessarily at the same time as the highest voltage operating conditions. VoC tends to be specified at Standard Test Conditions which has light-levels representative of a sunny day (1000 W/m2) and a cell temperature (not ambient) of 25 degrees C, which is already a lot cooler than most panels would typically be at that level of irradiance. So really, the label is already specifying a voltage higher than what you would typically experience during times of max generation.
However, the max voltage could exceed this rating at times when there are cold ambient temperatures with enough light for the module to function, but not enough sun to meaningfully heat the cells. So in this scenario you may have maximum voltage, but you're far from maximum power nor at 'ideal conditions'.
What does “maximum possible voltage” mean for a solar panel? Do you include things like cloud edge effect (which increases incident light beyond direct sunlight?) What about installs with a nearby window reflecting light onto the panel? Do you include ultra-cold environments (which will reduce the resistance and therefore often increase voltage, although admittedly not, I think, Voc)?
VoC is the maximum potential voltage a cell is physically capable of producing. It does not consider real-world conditions. Rather, real-world conditions cause the solar panel's output voltage to be somewhere between 0 and its VoC.
Obviously you include everything, otherwise it wouldn't be a maximum. You can define a minimum temperature for this, of course, but the customer should know about it.
Why does the Delta Pro not have a fuse on the input, with the MPPT limiting the max voltage to 150v (by upping the current until the voltage sags and/or the fuse blows, or even a straight crowbar circuit). This is a premium consumer brand selling a mostly complete product, and protecting the input from overvoltage would be straightforward. The frustration at the warranty weaseling isn't surprising.
You might think that the voltage rise could be too fast for most protective technologies to save the downstream electronics, but the general case is that the temperature slowly drops and the sun slowly rises. So the voltage should slowly approach the limit.
Adding a normally-open relay and a voltmeter and a microcontroller should fix this. Relay won't close on startup unless the voltage is safe. Microcontroller will open the relay if the voltage gradually nears the limit. Should be solvable for <$5 in parts.
Dark start (when the batteries are flat w/o grid power) will be challenging. There will need to be a small battery to power the voltmeter and relay, or a high-voltage tolerant supply to power the microcontroller and relay temporarily. A 9V should likely be sufficient.
Common relays don't handle 150VDC, and I'd spec the voltage even higher even though one would think the voltage rating has more to do with arc interruption rather than creepage while off. Also a microcontroller is complete overkill, draws too much current to be easily powerable by the solar panel side, and adds complexity for something to go wrong. A simple analog comparator suffices.
The standard answer for overvoltage protection is a crowbar circuit + fuse, and I think that's what I'd aim for rather than a relay. The problem with DIYing that is knowing the input capacitance of the Delta and finding out whether it has any other problems with its input being abruptly shorted.
No the DC/DC converter could just turn it's transistors to short out the panels and rely on the fuse you want anyways to handle idiots paralleling more panels than allowed.
Why isn't there code/regulations for tbis. Why do you need blog advice.
It is like using too thin wiring to your oven or something. Because you based it off how you typically use the oven not is max draw plus decent margin.
Which is why you get a qualified electrician who knows or get qualified yourself.
> Why isn't there code/regulations for tbis. Why do you need blog advice.
On pretty much every other device (domestic for sure, I don't actually know abount commercial) there is.
> It is like using too thin wiring to your oven or something. Because you based it off how you typically use the oven not is max draw plus decent margin.
Sure, but with all other electrical labelling the numbers are correct. Imagine if Neff said "you only need an 13A rated socket" for their oven, and then when you want to bake bread it draws more. That's very different to Neff saying "you need 45A", and deciding to install it on a 13A socket yourself because you don't need to make bread. The former is what's happening in this case.
Quote from the internet in reference to 10mm2 wire gauge:
"This metric wire size is common in industrial settings for high-power devices and main circuits where thicker conductors are needed for safety and efficiency."
Most household solar systems do require permitting and inspections before you can turn it on. There are some exceptions in a few states for very small systems now. Ecoflow provides equipment for these small legal unpermitted installs.
More importantly, equipment shouldn’t self destruct in a dangerous fashion when pushed over the limit.
When I got solar panels for my (former) house 15 years ago, as I recall, the best practice was to have panels in parallel (each with its own microinverter) and not in serial as serial would cause loss of efficiency when there was partial blockage of panels. (I could be misremembering all of this).
That's only relevant if you're so starved for panel area that you can't put them into places that have each sub array sufficiently homogeneous and only partially shaded during sunrise/sunset.
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And no matter what happens, customer support should help the customer, not blame them.
That is the issue is with the wrong labeling of things that are being plugged into this vendor's device, not the vendor's own labeling.
I agree the labeling is an issue here, but the solution must come from the wider industry or regulatory bodies; the alternative is for vendors to switch to their own pseudo-units to internalize the math, which would not be good for customers either - think "ACME Generator2000 accepts up to 4 Power Units of input; each ACME SuperEco Panel supplies 1 Power Unit, or 1.5 Power Units if you're in Canada...".
Saving users from having to do a little thinking to not brick their device is a tried-and-true excuse for vendor lock-in in our industry :).
So given that in almost all use cases, you can have 2 panels in series, they should just say “max 2 panels in series”. Simple.
A good product hides complexity from the user with sane defaults and optional advanced configuration. This feels like the same problem.
As it is, panels are gonna produce variable power depending on the weather. Putting interoperability with third-party panels aside, to get the simplicity of "max 2 panels in series", they'd have to either cap the max power on the panel/generator link and dump the excess, or set the limit based on the worst case a customer is likely to encounter. I.e. they're either gonna waste power, or gouge their customers for extra hardware. Neither of that makes sense for an ecological product sold to a price-conscious customer base :).
Idk. I don't have a PHD, but 220V sounds like 240V to me. I wouldn't do this.
I feel like getting advice about how to wire up electronics should not be so hard.
> Maybe they should just improve their product to make it more resiliant
Adding "resilience" usually adds to the per-unit cost. I think making a web page adds some cost too, but at least that can be amortised.
> And no matter what happens, customer support should help the customer, not blame them.
I think that's happening here: Making a web page to educate future customers seems like a really good idea. I wouldn't have thought that necessary until I saw it, but I'm always excited to learn something new.
The existing customers who did dumb should consider this a relatively cheap education in electronics; cheaper than a PHD at least!
Also, whether the company also gave them rebates or credits we don't know here, but telling "customer support" they "should help the customer" is also telling them they're not helping the customer, and you don't know that.
In this case, the cost is much less than a dollar (say, a varistor that blows the existing fuse) and it prevents a catastrophic failure.
I don't think this is an official website of ecoflow.
Other than that I agree. I don't think asking for a bit of knowledge from the customers is a bad thing. A warning in the manual about safety factors should be enough.
220[Vrms] * 1.414 = 311[Vp-p] btw. HOW!?
Yeah, this sounds very much like "you're holding it wrong".
https://www.se.com/us/en/faqs/FA104355/
I think if you work with electrical or electronic systems in practice, you learn pretty quickly to respect tolerances and that data sheets are a map, not the territory.
Also, electrical installations are usually seen as a field that should be done by trained personnel, not arbitrary laymen home owners. So I think the appropriate reaction would be to remind people that they should hire an electrician to do the installation, if they don't have the necessary specialized knowledge themselves.
This world is amazing anything runs at all. The slightest addition of complexity is causing everything to fail now.
Modern computers are less reliable than ever, some companies have decided to REMOVE the pinhole bios reset (that has been around for 30 years) at the same time as things are buggier now and dont boot again until you physically unplug the bios battery deep inside and hard to get to.
Whether or not the company in this case shares some or most of the blame with novice users - the analogy is not a great one.
Unless it’s safety critical, you usually don’t want a system with a bunch of active electronics to prevent someone wiring it up wrong, because those components will interfere with whatever you’re hooking it up to, such as the MPPT, the battery, or whatever else.
This is like how AA batteries have a nominal voltage of 1.5V but the actual open circuit voltage is 0.9V~1.65V depending on charge level, temperature, etc. If you connect an AA to something that’ll explode at a voltage of 1.55V, that’s on you.
Similarly if you buy a 470 ohm resistor, you will find in on the data sheet that’s usually at 20°C. To know what it’ll be at any other temperature, you’ll need to use the temperature coefficient to calculate it.
You started off by saying you don’t know about the components they’re selling - but that turns out to be absolutely critical to understanding the context here.
Either way, I can’t believe they just let it fry the main board instead of having a sacrificial fuse or equivalent go first in these scenarios, whether it was a product aimed at professionals or not. It’s just dumb.
So say, the input is rated for 150V, spec the components to sustain 180V, and trigger the MOSFETs to disconnect the panels at > 160V.
And maybe also add a big ass buffer capacitor, that can be used to soak up a bit more energy in the case of an inrush spike before the MOSFETs actually disconnect.
DC starts getting really nasty to deal with somewhere between 36-52v, with 150v of panels not being something joe-blow should be able to buy on amazon. Designing these systems to be safe is difficult.
Too much current is a heat dissipation problem, and you've got some time to deal with that, at least tens of milliseconds.
Anyone have a teardown on these things? Are they using under-rated MOSFETs? That's all too common in solid state relays from China.
Not seeing UL certification on this thing.
If we're going to have US protectionism against China, a good first step would be to require UL-type testing, carried out in the US, on all imported electrical devices that run on more than 12VDC or contain a battery chemistry capable of thermal runaway. Electrical safety is a solved problem if you can keep people from cheating.
[1] https://toshiba.semicon-storage.com/eu/semiconductor/design-...
This appears to be a situation where the engineering team determined the absolute maximum input voltage and the marketing/product people put that number straight into the documentation.
Standard practice with electronic parts is to determine the absolute maximum rating, then to specify a recommended maximum that allows for some safety margin and variation.
Instead, this company determined the absolute maximum and then just shipped it.
Yet so many people in this thread are so keen to blame the customer, it’s pure ego from them. “I’m too smart for that to happen, so it’s all their fault!” they sneer. Classic bad faith forum behaviour…
I don’t think this analogy works. The solar input works like Diesel or Gasoline in different temperature. It’s pretty unreasonable to assume the consumer knows when depending on temperature unless the explicitly state in the manual (I’m willing to bet good money majority of the people in US have never read their car manual either)
Diesel is blended differently for winter and summer in many countries. See this for instance https://www.crownoil.co.uk/guides/winter-blend-vs-summer-ble...
Around the skiing season, many automotive magazines will remind diesel drivers to buy “winter diesel” or use additives if e.g. driving up to the Alps or similar cold places.
It’s not so black and white :)
Sometimes they can be ok pedagogical tools, but they're easily misused as tools of persuasion.
(certain fuel systems components will be degraded by high ethanol gasoline)
https://www.researchgate.net/figure/Module-voltage-current-v...
Basically anything that consumes solar power incorporates what's called a "MPPT", or maximum power point tracker.
Basically, it's a smart DC-DC converter that continually tracks the voltage/current output of a solar panel and adjusts the load to extract the maximum available power from the panel.
It's not uncommon to have issues with extremely high panel voltages in snowy climates, when they're first illuminated in the morning. If you are close to the maximum voltage your MPPT charger can handle in normal circumstances, extreme cold can even damage things during the initial morning transient. You then have to do oddball things like use a crowbar system to prevent blowing up your MPPT system.
(see https://en.wikipedia.org/wiki/Maximum_power_point_tracking )
This is just like not upsizing wire gauge if you have a bunch that are loaded simultaneously buried together in a somewhat insulating wall. Without the burying under plaster, everything would be fine. But combine that with simultaneous loading during summer, and you fry/roast the PVC insulation.
Those things are normally built to handle a nominal 115 V assembly of panels. There's probably something on the manual about this, but when you put a giant label saying your device supports 150V, people are not going to read the manual.
Is EcoFlow advertising a higher input voltage than their products can actually take, assuming most people won't actually reach it due to temperature inefficiencies? That'd be false marketing, and it'd make this article manipulative, false blaming of the customer.
STC ("standard testing conditions" for solar panels) is 25C so if it's freezing 0C you have 25 multiplied by 0.33 Volt = 8.25 Volt more than STC in open circuit situation.
Unfortunately inverter manufacturers seldom document how many Volt will destroy the MPPT and up to how many Volt the MPPT will safely turn off by itself before breaking.
Solar panels are current sources that waste their power into a long string of silicon PIN diodes that eventually reach their forward voltage and begin to eat up all that juicy current. You can just take the current and keep the voltage as low as you want, just make sure to take all the current or it's voltage will rise to let the diodes take the current you aren't using.
I think this is where the confusion arises - what do you mean by ideal conditions? Ideal conditions for solar generation are not necessarily at the same time as the highest voltage operating conditions. VoC tends to be specified at Standard Test Conditions which has light-levels representative of a sunny day (1000 W/m2) and a cell temperature (not ambient) of 25 degrees C, which is already a lot cooler than most panels would typically be at that level of irradiance. So really, the label is already specifying a voltage higher than what you would typically experience during times of max generation.
However, the max voltage could exceed this rating at times when there are cold ambient temperatures with enough light for the module to function, but not enough sun to meaningfully heat the cells. So in this scenario you may have maximum voltage, but you're far from maximum power nor at 'ideal conditions'.
Adding a normally-open relay and a voltmeter and a microcontroller should fix this. Relay won't close on startup unless the voltage is safe. Microcontroller will open the relay if the voltage gradually nears the limit. Should be solvable for <$5 in parts.
Dark start (when the batteries are flat w/o grid power) will be challenging. There will need to be a small battery to power the voltmeter and relay, or a high-voltage tolerant supply to power the microcontroller and relay temporarily. A 9V should likely be sufficient.
The standard answer for overvoltage protection is a crowbar circuit + fuse, and I think that's what I'd aim for rather than a relay. The problem with DIYing that is knowing the input capacitance of the Delta and finding out whether it has any other problems with its input being abruptly shorted.
It is like using too thin wiring to your oven or something. Because you based it off how you typically use the oven not is max draw plus decent margin.
Which is why you get a qualified electrician who knows or get qualified yourself.
On pretty much every other device (domestic for sure, I don't actually know abount commercial) there is.
> It is like using too thin wiring to your oven or something. Because you based it off how you typically use the oven not is max draw plus decent margin.
Sure, but with all other electrical labelling the numbers are correct. Imagine if Neff said "you only need an 13A rated socket" for their oven, and then when you want to bake bread it draws more. That's very different to Neff saying "you need 45A", and deciding to install it on a 13A socket yourself because you don't need to make bread. The former is what's happening in this case.
"This metric wire size is common in industrial settings for high-power devices and main circuits where thicker conductors are needed for safety and efficiency."
That would be quite some oven.
Dead Comment
More importantly, equipment shouldn’t self destruct in a dangerous fashion when pushed over the limit.